Doctor Pretorius and the Lost Temple
by Paul McAuley

August 1832 
I first met the young engineer, and became entangled in the machinations of Dr. Pretorius and the affair of the lost temple, at a seance. For three weeks, fantastic stories of the psychic powers of a young Romanian gypsy woman had been circulating throughout London. It was said that she could relay messages from the dead and speak directly to the hearts and minds of the living, that her revelations and admonitions made women faint and strong men weep. Rank and fashion flocked to witness this latest curiosity; there had been numerous articles and sketches about her in newspapers and magazines, and skits parodying her seances put on in music halls and theatres. 
I was newly arrived from Edinburgh, and still wore a black band for my mother and father, but I was also young and full of misplaced confidence. I believed that I knew more about the matter of the dead than anyone living, and was both jealous of and intrigued by this young gypsy's fame; I knew that I must find out if she was a fraud, a rival, or a potential ally and friend. 
Her family had rented out the ground floor of a house on the northern edge of the Holborn Rookery, and a large crowd had gathered outside to watch the arrival of visitors to the new phenomenon. The unending procession of wonders that passes through the great metropolis never seems to exhaust the curiosity of its inhabitants; if the city were a theatre, it would never want for an audience, and its angels would see their investments multiply without any of the usual risk. Young women carrying babies or with small children clutching their skirts were begging for alms; unshaven ruffians in battered caps and canvas waistcoats were swigging from bottles; an old woman with greasy unbound hair and a shrewd gaze stood in a doorway, smoking a short clay pipe. There were pamphlet and ballad sheet sellers, orange sellers (the road was littered with the bits of tissue paper in which the fruit was wrapped), and sellers of ginger-beer and fried fish and pies. A crew of beggars lacking an assortment of limbs were got up as sailors in front of a sheet crudely painted with a ship foundering in a tempest. A street preacher stood on a box under a banner held up by his supporters, sweating into the serge of his black coat, his face shining and his fists shaking by his face as he tried in vain to make himself heard above the din. In short, every beastly aspect of humanity was on display, and most of them were in some way haunted, mostly by imps of delirium or the ghosts of dead children with faces like shrivelled apples; one old woman, bent double over a stick, carried a dozen half-formed ghost babies on her back, squirming over each other like blind newborn kittens trying to get their turn at their mother's teats. 
It was terribly hot, the close, heavy air laden with the miasma of every taper, candle, whale-oil lantern, and gas mantle burning in London's teeming night. Carriages were lined up along one side of the road, their horses waiting patiently in their traces, grazing from the nose bags strapped over their muzzles; the oaty reek of horse piss was the cleanest smell in the crowded thoroughfare. A pair of constables in black top hats and blue swallow-tail coats stood near a coffee stall, watching the burlesque with a kind of baffled approval, as if it had been unexpectedly staged for their benefit. I joined the knot of well-dressed men and women waiting to gain admittance, paid my florin to a whiskery old rogue who reeked of cheap gin (the grey hair tangled around his face swarmed with flea-sized imps), and followed the others through a dark corridor, hung with cobwebby threads and damp rags that brushed unpleasantly against my face, into a hot airless room not much illuminated by the half dozen candles spiked to the walls. There was a filthy piece of red velvet stretched across the rear wall, a sagging armchair set in front of it, nothing else. 
The audience was much as I had expected: a party of young swells in bright waistcoats given to laughter and loud remarks that were far less amusing and original than they supposed; several dignified old women in widow's weeds; a variety of the pale, anxious, recently bereaved. The only person of immediate interest was a white-haired man in an antique jacket and high-collared shirt, with a faint ineradicable sneer on his face and a bright, bird-like gaze that roved around the room. It settled on me for a moment, took note, and moved on. I was pinched toward the back, between a slight young man with the black hair and olive complexion of a native of Southern France or Spain, and a married couple, the woman in black with a veil across her face, her straight-backed husband attempting to seem dignified, but trembling with barely suppressed emotion; it was to his leg that the dead child clung, a stout but wan little thing no more than six years old. 
There were other presences in the room-blurred partial shells of the kind cast off in moments of intense emotion, and a foggy, bloated imp that peered out of the black shawl of a sharp-nosed old woman whom I took for one too fond of laudanum-but the little girl was the only true ghost. She looked at me with a kind of wonder, her eyes dark smudges, and asked in a tiny voice only I could hear if I would help her sleep. 
I smiled down at her. Like her father, I was also possessed by emotion; a sick anticipation revolved like a ball of hot tar in my stomach. 
"I'm so tired," the poor creature said. "I want to sleep and I can't. I'm so tired." 
She was too young to know what had happened to her. Like most ghosts, she was frightened and pathetic. 
I had an idea that she might prove useful, and said quietly, "Be patient, my dear, and I'll help you sleep for as long as you like. But first, will you help me?" 
She gave me a wan smile, and nodded warily. The young man beside me must have heard me talking to her, for he frowned and seemed to be about to ask me a question, but at that moment the grey-haired, imp-infested old man who had taken the admission money limped around the edge of the room, leaning on a stout stick and pinching out all but one of the candles. He took up station in front of the chair, stamped his stick on the floor for silence, and made a long meretricious speech I won't trouble to repeat in any detail, explaining at the end that all questions must be directed through him, and that if anyone would like to contact 'the other side' for the modest fee of just a half guinea, then they should now step forward, and tell him the name of their dear departed. 
Since most in the room had come there for that purpose, this took some time. The old man wrote down their requests on a scrap of paper, licking the point of his "permanent" pencil at every other letter, so that his lips were soon stained quite blue. I watched with growing impatience and dissatisfaction, already suspecting that I had squandered a florin to no good purpose. There was nothing of the matter of the dead here; only shabby showmanship and cheap spectacle. The swells passed around a silver flask and nudged each other; the olive-complexioned young man impatiently consulted a pocket watch; the white-haired man and I exchanged a glance, and his smirk grew a fraction, as if he had detected in me some impropriety. 
The married couple with the ghost child were the last to murmur into the old man's ear. He licked and wrote, then tucked the pencil behind his ear and struck the floor with his stick. A corner of the red drapery was lifted to admit, with a great swirl of sweet-smelling white smoke, two burly men in collarless shirts and braces, escorting a plump girl of fourteen or fifteen in a plain black dress. She was endeavouring to seem calm, but I saw how her gaze darted around the room, and how she flinched when one of the men took her arm and led her to the chair. 
I told the little ghost to go and stand before the lady, and when she showed reluctance to let go of her father said, "Be brave now," and gave her the tiniest pinch of compulsion to thrust her through the crowd. 
The remaining candle went out as soon as the plump girl sat down. A woman gasped; the swells tittered. Then someone uncovered a lantern and a ray of light shot across the room, transfixing the gypsy girl's face. Her eyes were rolled back, showing only crescents of white behind flickering eyelashes, but I did not for a moment believe that was why she did not see the little ghost who stood in front of her. Bells rang here and there in the darkness and pale shapes flew through the air. The swells cheered; several of the women emitted muffled shrieks. The gypsy girl's arms and then her whole upper body began to quake. Foam dripped from a corner of her mouth and she suddenly bent double, as if punched in the stomach, and began to chokingly regurgitate into her lap yards of white stuff. The little ghost watched this calmly, once or twice glancing back at me. The smoke grew thicker, defining the angled beam of the lantern. When she had spat out the last of what was clearly meant to be ectoplasm, the girl raised her face to the smoky light, like a burlesque of a blind Pietà, and asked in a croaking, thickly accented voice if there was any spirit who would speak with the living. 
I could no longer contain my impatience and disgust, and said loudly, "There is a ghost already here, madam. Perhaps you could point it out." 
The audience stirred, trying to discover who amongst them had spoken. The girl repeated her question, like an actor insisting on the script after someone else botches a line or a piece of scenery falls over, and the old man said, "Let the unbeliever leave now, for the sake of those who want to speak with the dead." 
My anger was a hot pulse behind my eyes. I said, "If you know anything about the matter of the dead, sir, you would have your daughter describe the poor shade who stands before her." 
My eyes were adapting to the darkness. I could see that the two toughs on either side of the girl were looking this way and that, trying to locate me. The little ghost was looking at me too, plainly uncertain that she had done all I had asked of her. The olive-skinned young man stepped close and dug a sharp elbow in my ribs and whispered, more with delight than anger, "What the devil are you about, sir?" 
The old man thumped his stick three times on the floor, and said, "There are many spirits here. Let them show themselves." 
The bells rang again; again, pale shapes shot through the near dark, crossing the room in one direction and then the other. I whipped the blade from my cane and swiped at one of the filmy shapes; the two toughs must have seen the blade glancingly catch the lantern's light, for they began to move toward me. 
I said, as loudly as I could, "This is a fraud, sir! A shameful sham! If she cannot even see the ghost that stands plainly before her, how can she raise any spirits?" 
The swells cheered; the toughs pushed through the crowd and took hold of my arms; there was a brief and undignified struggle as they wrestled me toward the door. For an instant, I managed to turn back and catch the gaze of the little ghost and give her the oblivion she so badly desired. One of the toughs tried to wrench my blade from my hand, but I would not let it go, and carried it high before me, with the captured scrap raised above my head like a battle flag. Behind me, the old man was thumping his stick on the floor and saying loudly that his daughter's trance was broken and the session was ended. I shouted again that she was a fraud, that she could not even rid him of his infestation, and then I was borne out of the room. 
I suppose that the toughs would have found a quiet spot where they would have taught me a short, sharp lesson, but the young man followed on their heels, loudly protesting at my treatment, and got the attention of the two constables as we all tumbled out into the street. The blue-coats started toward us, and the two toughs, suddenly uncertain, loosened their grip. I shook myself free, and the young man took hold of my elbow and pulled me through the crowd of onlookers. A police whistle squealed hoarsely, people cheered, a flung bottle turned twice in the air and smashed against a wall, and we both ran. 
We did not stop until we had put two or three turns of the narrow lanes behind us, and leaned against a wall, out of breath and helpless with laughter. 
"I hope, sir," the young man said, when he was able to speak, "that you have good evidence that those people are charlatans." 
I showed him the scrap of muslin caught on the end of my blade. "Pulled through the air on wires," I said. "Likewise, wires worked the bells concealed in the ceiling." 
"And the stuff she choked up?" 
"Muslin also. Performers learn to swallow stuff and bring it back up again. The whole thing was no more than a theatrical trick, got up to gull the desperate and the unwary." 
The young man studied me. He was a good foot shorter than me, and slightly built, but was possessed by a restless, barely contained energy. His eyes were very dark, almost black, and his gaze burned with purposeful intelligence. "If it is a charade, then what of you, sir? Are you a journalist from one of the newspapers, sent out to expose it? And if so, are you truly in mourning, or is that arm band as much a sham as the show you so effectively wrecked?" 
"I know something of these matters, that's all. And I can assure you that I am genuinely in mourning: for my parents." 
My anger had quite gone, although a few imps clung to me still. I brushed my hand through my hair, dismissing them, and felt foolish and ashamed. One of the most important disciplines in the matter of the dead is to learn to control the baser emotions, and in my disappointment and frustration I had let them master me. 
"I am sorry to hear of your loss," the young man said, "but I think that you did not come here to contact your mother and father, for you did not step forward and pay the half guinea." 
"Neither did you, sir." 
"I was cursing myself for a fool as soon as I entered that room. I imagine that anyone who can truly speak with the dead, if there is such a person, needs no theatricality." 
"That's very true." 
"You mentioned a ghost." 
"The couple who stood next to us had lost their first child. I should not have spoken of it. I really should not have spoken at all. Most of the people there were so undone by the loss of a loved one that they were willing to believe in anything, as long as it gave them a little comfort. I took away even that." 
The young man studied me for a moment more, and then, as if coming to a decision, suddenly thrust out his hand. "My name is Brunel, sir. Isambard Kingdom Brunel." He paused, head cocked, as if expecting me to recognise the name, then said, "I suppose that I came here because I am also desperate." 
I took his hand and told him my name, and thanked him again for his help. "You risked your life in saving mine," I said, "and I will be more than happy to give you any help I can. But I must say that you do not appear to be haunted, or troubled in any way that I can detect." 
"I have lost no relation, Mr. Carlyle," Brunel said. "What I have lost is my reputation, such as it is. I came here because of a murder. I hoped-" 
A police whistle shrilled, far off; another answered, much closer. 
Brunel took my arm. "We'll get out of this," he said. "I will tell you why I came here, and then we'll see if you can't be of some help to at least one poor foolish supplicant." 
He hailed a cab under the flaring gas lamps at the corner of Oxford Street and Tottenham Court Road, and after a brief argument with the driver, who swore that he could not travel south of the river because he would find no fare to get him back again, we climbed aboard and rattled away toward Waterloo Bridge. 
My new friend was not only an engineer; he was also the son of an engineer. His father, Marc Brunel, had devised an apparatus for tunnelling through soft ground or beneath water, and had won authorization from Parliament and backing from a group of wealthy subscribers to drive a tunnel beneath the Thames from Rotherhithe to Wapping. 
"It was an engineering wonder that excited the imagination of Europe," Brunel said, "but it has been blocked up for three years now, owing to the pusillanimity of the damned directors, who took fright after it flooded and let all offers of help slip by them." 
The project had got into difficulty from the beginning. Instead of the continuous stratum of strong blue clay promised by the geologists, the Brunels had encountered fissures and fractures where only gravel separated them from the bed of the river. In addition to the fetid conditions, and the consequent toll of "tunnel sickness" amongst the workers, the excavation suffered from two major inundations. After the first, it had taken six months to seal the cavity in the river bed with thousands of bags of clay, pump the water out of the shaft and twin bores of the tunnel, and remove the vast mound of silt which had been washed into the tunnel when it had been breached. Three months later, the river broke through again, and nearly claimed the younger Brunel's life. He grew very animated as he told me every detail of this disaster. He had been working at the face of the tunnel, and was quickly up to his waist in water. A shifting baulk of timber trapped his leg, and by the time he had freed himself and reached the stair at the end of the east arch, his way was blocked by men fleeing from the flood. He was trying to reach the visitors' stair in the west arch when a great wave broke upon him and, amazingly, bore him up to safety. 
The rush of the water was, he said, a very grand effect; he would have paid fifty pounds toward the expenses of such a spectacle, and instead had got it gratis. He was laid up for several months after his adventure, and by the time he had recovered his health, work on the tunnel had stalled for lack of funds. 
By now we had crossed the river and were rattling through narrow streets lined with grim, shuttered warehouses, and my companion broke off from his story and leaned at the open window, shouting up instructions to the cab driver. We had been travelling for almost an hour-such was the amazing size of the city-and I was beginning to wonder how I would ever find my way back to my lodging house when the cab drew up by a gate in a tall fence of tarred planks. Brunel paid the driver (who twitched the reins of his horse and clattered off in his boneshaker without a backward glance) and hammered on the gate until he woke the watchman. 
The gate opened onto a wide square waste, where heaps of bricks and sand and gravel and timbers lay in a great confusion of shadows and moonlight. There was a long low shed beside a rutted road, a tall narrow building of yellow brick with an even taller chimney at one end, and a timber-framed office beside a kind of open-sided byre one might expect to find in some remote Highland field; this rude construction sheltered the opening of the shaft which led down to the tunnel. Brunel unlocked the office and brought out and lit a lantern, sharpening the focus of its lens so that its beam shone inside the rim of the shaft. One half was boarded over; in the other, a cast iron stair screwed down into darkness. 
I said, "You would like me to examine the tunnel now?" 
"It's all the same down there, day or night," Brunel said, and treated me again to his sharp gaze, and smiled. "I must seem an impatient man, Mr. Carlyle, but once I've set my mind to a plan, I like to strike fast and sure." 
"And I am not a man to go back on my word. I said that I would help you, and so I will." 
Brunel led the way down the long spiral staircase, and held up his lantern as we came out on a platform of pine planking. The tunnel was much grander than I had expected: a brick floor sloping away into darkness, brick walls leaning back and meeting more than twenty feet overhead in a grand arch, with buttresses at regular intervals, and side arches through to the parallel bore. We scrambled down a ladder and walked along the gentle slope, our footsteps echoing dully on wet, slimy bricks, to the edge of a great wedge of black water that stretched away to a blank brick wall. 
Brunel explained that the tunnelling shield his father had invented was bricked up behind the wall, to prevent further inundations. It was, he said, a set of massive cast iron frames, six frames to each arch of the tunnel, each frame divided into three storeys to form thirty-six working cells. Experienced miners had worked in each of the cells, taking away one of the wooden boards that formed the working face, excavating a hand's-width of soil, replacing the board flush against the new face, and moving on to the next. When all the boards of a cell had been extended, the cell was jacked forward; when all the cells had been extended, the shield itself was moved forward. Thus the excavation had proceeded a few inches at a time, with bricklayers extending the arches behind so that only the very edge of the excavation was unsupported. 
"It was the narrowest of gaps," Brunel said, "but it was still hazardous, and it was made worse because the directors, damn them, grew impatient and ordered that it should be doubled, to speed up the work. My father and I knew that the ground was treacherous, but the directors insisted on it, and insisted on admitting sightseers too, despite the risk. It was only by great good fortune that the waters broke through when the arch was not full of visitors." 
Brunel had been watching me narrowly as he talked. Now he broke off from his discourse and asked if I was feeling quite well. 
"There are no ghosts here, sir, if that's why you ask." 
"Yet men have died here. Poor Richardson, and Ball and Collins, and the others …" 
"The matter of death is not as simple as the penny dreadfuls would have it, Mr. Brunel. You mentioned a murder. Who was it that was killed here?" 
"He was not murdered here at all, although I thought … Are you all right, Mr. Carlyle?" 
"A curious singing in my ears, and a sense of oppression." 
Brunel looked disappointed. "I feel it myself. I have calculated that when the Thames is in full flood, the tunnelling shield had to support upwards of six hundred tons." 
A strange compulsion made me walk forward. My boots splashed into shallow water and I was suddenly as thirsty as a Bedouin, and knelt and scooped up a palmful of water and sucked it down. I felt it writhe like a worm in my throat and tasted thick warm blood; at the same moment, the arch of brick above groaned, and I felt, distinctly, that I was in two places at once. I was kneeling in the black water, and I was pressed flat by a great suffocating weight, as in one of those nightmares in which we cannot flee the frightful horror advancing upon us. 
Then Brunel was hauling me up by the armpits, and the spell was broken. My right hand hurt like the devil, the taste of blood was thick and foul in my mouth, and the little lake was as choppy as a storm-tossed sea. The arch of the bore groaned again, and Brunel said, "Sometimes the ground above shifts with the tide." 
"Something is lost," I said, although I did not know why. 
Brunel held up the lantern by his face and studied me and said, "If there are no ghosts, you would make a passable substitute for one, Mr. Carlyle. Let's get above ground, and find something to warm our blood." 
Inside the long shed, he poked around in the drawers of a huge desk, pulled out a bottle of brandy, poured generous libations into two tin mugs, fastened my fingers around one, and settled a blanket around my shoulders. The brandy burned through the thick foul taste that coated my mouth and tongue, but my hand still ached-it was as if someone had wrapped a hot wire around the base of the forefinger. Brunel sat in a chair opposite, his hands on his knees and his elbows square, and sipped his brandy and watched me take in my surroundings. The space where we sat had been made over into an office, with the desk at one end of a big, square carpet, and a table and chests with ladders of narrow drawers below racks of pigeonholes at the other. Beyond was a gloomy workshop, with work benches, a lathe and a drill press and other machinery, glass and glazed ceramic carboys in wicker baskets, racks of copper piping and sheet metal, and half-finished or half-dismantled machinery. 
I said, "I must apologise once more, it seems." 
"You said that something was lost, Mr. Carlyle. Can you tell me what it was?" 
"I don't know why I said it. Perhaps you should tell me the rest of the story. Someone was murdered, I believe." 
Brunel got up and walked about the perimeter of the carpet for a few moments, fingering a silver circular slide rule he had pulled from one of the pockets of his waistcoat. I was to learn that he was always too full of energy to sit still for long. He had to be up and doing things even while he thought. 
"We employed two sorts of labourers," he said. "The men at the face of the tunnel, working on the frames, were skilled miners, my corps d'élite. I would trust them with my life. The rest were mostly Irish navigators, who worked the hand pumps and transported the soil from the excavation. They were good enough fellows, and worked hard and for the most part uncomplainingly, but they were men released from the useful influence of domestic ties, and as a consequence were easily led into temptation, particularly on pay day. They were much given to drinking their pay as quickly as they could, even though we provided beer at the end of every shift, to ease their suffering after working in such difficult conditions." 
He was still walking to and fro, his hands shaping expressive gestures in the air. 
"On the whole, I found them very manageable, but there were one or two rogues, and one or two frank criminals to boot. One of these was a man by the name of Coffee Joe, so called not for his liking of the reviving bean, but because he was so often in drink that he deserved the sobriquet less than anyone else. I've told you how close we dug to the riverbed. Quite often, small objects dropped long ago into the river would be washed through by small runs of water. Leather shoes, the square nails used by shipwrights, buckles, glass bottles, even a coin or two. Any other man finding such an object would present it to one of the foremen, but Coffee Joe was known to keep his finds. I heard a rumour that he had sold an enamelled dagger handle to an antiquarian for ten shillings, but put it down to envy, and did not dismiss him. He was a hard worker, despite his liking of drink." 
"But he found something else," I said. Despite the warm fug of the brandy, the forefinger of my right hand still felt as if it was being slowly amputated. 
"That's how the story went," Brunel said, "although I heard about only after the last, fatal flood. Some of the men cursed Coffee Joe, even though by then he had quit the site-he had, in fact, been arrested for his part in inciting a drunken riot in a tavern. The story was that he had taken something which he blamed for a change in his luck. He claimed to be haunted by water. It would bubble up between the flags of the wretched cellar where he had a bed, the spray of public fountains would drench him, pumps would spit mud at him, and so on and so forth. And he had bad dreams, he said, of floods, not just of water-" 
"But blood," I said, the taste of that substance for a moment so thick in my mouth that I thought I might choke on it. 
Brunel had stopped at the far end of the carpet, and was watching me closely. He said, "When you took that draught of water, and the flood pool grew so agitated, I knew that it was something of the same matter. Is it a ghost?" 
"If it is, it is the most potent and undetectable ghost I've ever known." 
"And you have known some, in your time." 
"I will admit to the acquaintance of a few, Mr. Brunel. What happened to Coffee Joe after he was arrested?" 
"He was sentenced to transportation to Tasmania and three years hard labour, and at the end of it he found his way back to London." 
"A navigator indeed." 
Brunel agreed. "He was found dead just five days ago. One of his former fellows heard of it, and communicated it to me." 
"He was, perhaps, drowned?" 
"He was found with his throat cut. I spoke to the Inspector who investigated the murder. He said that the cellar in which Coffee Joe's body was found was drenched with blood, and the fatal wound had been so savagely inflicted that the head was almost completely severed." 
"This was the same cellar in which Coffee Joe had nightmares of drowning, years ago." 
Brunel looked at me, and raised one of his vigorous black eyebrows. 
"He travelled halfway around the world," I said. "I must assume that it was because he wanted to find something he had left behind-and where else might a man like him leave it, except in the one place in the world where he could lay his head of a night? And he must have been desperate to find it, because it is against the law for a transportee to return to this country." 
"I've thought long and hard about that," Brunel said, "and I must admit that it still puzzles me. I agree that it must have been something he was desperate to find, yet it must also have been of little intrinsic value. He had not sold it, you see, and he was the kind of man who would sell his shoes if he was in need of a drink. But someone else wanted it, badly enough to kill him for it." 
"That is why you wished to interrogate his ghost." 
Brunel began to walk to and fro again. "The men said that Coffee Joe had put a curse on the whole endeavour, Mr. Carlyle. And the whole thing did indeed go smash and all to blazes after he left. The affair has reduced my father to working catch-as-catch can-he is away at this very moment, surveying the route of a canal near Oxford. And I am in much the same situation. We have never shirked hard work, and we have always faced up to disaster, done what we can to overcome it, and put it behind us. I have done my share of odd jobs, too, and I have my gaz project," he said, gesturing towards the machinery heaped beyond the office space, "although I fear now that all the work I have done on that is no more than the building of a castle in the air. Perhaps our bad fortune was no more than unlucky geology and bad faith on the part of the damned directors. But perhaps there is more to the matter than that." 
"What prompted you on this track, Mr. Brunel? You're an engineer. You are not the kind of man who usually becomes involved in the matter of the dead." 
"You have a sharp mind, Mr. Carlyle. Yes, I'm sure that I would have dismissed the rumours about Coffee Joe and the matter of his murder if not for one other thing-my own dreams. The work on the tunnel proceeded day and night, and I often caught a few hours sleep in a cot in the office. Toward the end of it, I often had nightmares of floods and collapses, but I paid no attention to them because we all had such nightmares after the first inundation. But a few days ago, the day that Coffee Joe was horribly murdered, the same dreams returned, and have done so every night since." He looked straight at me, with a defiant glare. "There. Now I have told all, and you can believe it, or call me a fool." 
"Before I do anything else, I think I must look at Coffee Joe's cellar, and see what I can find there. And for your part, perhaps you should consider dredging the river above the tunnel. I believe that something lying there may provide the key to the affair." 

· · · · · 

We drank brandy and talked into the small hours of the night. We set our plans straight. I described several of the cases I had worked on in Edinburgh, and Brunel politely pretended to believe every detail. Despite what he had seen in the tunnel, he was still greatly sceptical of the matters to which I had dedicated my life. He talked a little of his own plans, and I quickly learned that although he was hard-headed and pragmatic, he was no utilitarian Benthamite. He was, in fact, as brimful of imaginative sympathy as any poet or painter, realizing his dreams in bricks and iron rather than in words or paint. Artists seek to move the minds of men; Brunel had enough energy and ambition to move the world itself, if he could but manufacture a lever large enough, and discover a suitable fulcrum. He had been working on the gaz engine experiments for two years, or, as he put it, one tenth of the remainder of his life, but with no great success. "And now I fear that I am coming to the conclusion that no sufficient advantage over steam power can be obtained," he said. "I have spent all my time and considerable money building a chateau en Espagne, and now all my fine hopes have fallen into ruin. But there it is, and it can't be helped. I had hoped by now, Mr. Carlyle, to have laid the foundations for my fame and fortune, but the tunnel is dead, the gaz experiments are as good as dead … Well, well. If I can make no other living I will do so by the example of my father, working where I can for whom I can." 
There was a considerable anguish hidden behind Brunel's careless dismissal of his bad fortune and failure, and I saw now why he had hired me. Although he would never admit it, it was a last desperate attempt to revive the fortunes of the tunnel, and thence of himself and his father. 
It was too late to make my way back to my lodgings when at last we ran dry of both brandy and conversation, and I slept for a few hours on a cot in Brunel's office while he curled up, like a cat, under his own desk. I had no dreams worth remarking on, and neither did Brunel, who when he woke was as spry as if he had slept twelve hours straight through in a featherbed. 
"Perhaps your intrusion somehow ended it," he said. 
"If only it was as simple as that," I said. 
"I know. You must make your enquiries, and I must make mine, and we'll meet again as soon as we can." 
I bade farewell to my new friend, and walked west and then north through the wakening streets. The air was already close and warm. Streams of clerks, shop workers, labourers and porters were walking toward their work places, joining the great river of humanity that flowed across London Bridge into the City, the tramp of their feet shaking the ground quite as much as the carts and coaches rumbling along the main road. In the brightening morning light that shone along the ship-choked river, the thousands of people, all moving in the same direction, all clad in the costumes of their trade, seemed like a carnival parade, and the air was full of conversation and laughter, and cheerful greetings sung out to friends and workmates. 
But here and there amongst the tide of the living, like spies and secret agents from some dolorous power, were the dead, walking with bowed heads and shuttered faces, drawn toward their former workplaces by ineradicable habit, unnoticed by any but me. 
I escaped the crowds, and the annoying attention of certain of the dead, in a coffee shop, where I enjoyed a fine breakfast of muffins toasted on a sea-coal fire and spread with butter and white honey, a plate of chops and kidneys and pickled onions, and a pot of bitter, strong coffee. Refreshed, and provided with directions by the waiter, I walked through the City and against the slakening tide of people flowing toward it from the new suburbs of Islington and Holloway, to my lodging house in Barnsbury. 
It was a fine terrace house of four storeys, built just ten years ago on a rise above the Caledonian Road, with iron railings in front and views north toward the fields and woods of Highgate. The lady of the house, Mrs. Rolt, shot out of her parlour as I entered, and told me that I had missed a caller by just half an hour. 
"A strange old gentleman," she said, fixing me with a stern eye. "Perhaps I speak too frankly, but I'm not entirely sure, Mr. Carlyle, if I approve of him." 
My visitor had not left a card, but he had made a great impression on the indomitable Mrs. Rolt, a stout woman of middle years whose husband, a solicitor's clerk in the City, was by contrast as meek a man as you could ever wish to meet. She told me that my visitor's name was Dr. Pretorius, and described him in enough detail for me to recognize immediately the haughty, white-haired gentleman who had attended the seance last night. 
"He would not state his business," Mrs. Rolt said, "but he did tell me that he would call upon you again. I would prefer it, Mr. Carlyle, that you did not make this house your place of business. Especially if your business involves men of his kind." 
"His kind, Mrs. Rolt?" 
I was wondering of course, how this Dr. Pretorius had discovered my lodgings, and wondered too what else he might know about me. 
Mrs. Rolt said, "He was polite enough, Mr. Carlyle, and he spoke English exceedingly well-too well, if you follow me-but there was something sly and crafty about him. It was as if he was somehow playing a joke on me with his politeness." 
"Are you implying that he is a foreigner, Mrs. Rolt? And am I to understand that you believe that any foreigner should not be trusted?" 
"I get on well enough with anyone who is straightforward with me, Mr. Carlyle, and I'm afraid to say that this gentleman had something crooked about him, for all his politeness. Pretorius-that's no kind of name at all, not even for a foreigner. How can anyone trust a man without a proper name?" 
I found myself apologising for my visitor, and tried to escape up the stairs, but Mrs. Rolt was not quite done with me, asking that I should take care to inform her the next I was going to be out all night. 
"I'm afraid it was unavoidable," I said. "A sudden business engagement." 
As I said this, I realised with a sudden rush of happiness that I had taken on my first client since I had moved to London. 
"Your boots are muddy, and there's mud on the cuffs of your trousers, too," Mrs. Rolt said, not unkindly. "Bring them down when you are ready, and I'll have Jenny clean them for you. I like a clean house, Mr. Carlyle, and a quiet one, too." 
"And so do I, Mrs. Rolt." 
I had chosen my lodgings precisely because the house was quiet-not in the way Mrs. Rolt meant, but because it was too new to have accumulated much in the way of ghosts. I had tucked moly and rue here and there, to keep out unwanted visitors, and I checked these precautions before I took to my bed and slept for a few hours-one of the disciplines in the matter of the dead is to take rest when one can. It was noon when I rose. I washed my face and hands and changed my clothes. I cleaned my boots myself, but took my muddy trousers down to the basement for the attention of the maid, Jenny. I informed Mrs. Rolt that I had a great deal of business today, so that she should not trouble to lay my supper by if I was late returning, and went out. 

· · · · · 

Brunel had given me the name of the Inspector of Police who had attended the scene of Coffee Joe's murder. After I had taken a lunch of salmon and shrimp sauce at a dining-house, I found him in an airless, whitewashed office at the busy police station at Holborn. A stout, harassed man with thinning gingery hair and a red, sweating face, he read and reread the letter of introduction Brunel had provided, and put me in the care of a blue-coated constable, who escorted me through the tangle of narrow alleys and lightless courts of St. Giles Rookery to the cellar. 
It was a bleak, mean place, filthier than any stable, with a ceiling that sagged so low the burly constable had to stoop, and barely lit by a narrow, barred window where a brace of urchins peeked in. A heap of dirty straw and dirtier blankets was piled up along one wall, and most of the flagstones of the floor had been pulled up and flung aside, and the dirt beneath them was greatly disturbed and dug over. It was damp, and stank horribly of unwashed bodies and of rotten blood. There were black bloodstains on the walls and the overturned flagstones. There was also an imp posted in one corner, a vile little thing with a bloated frog's belly and a tiny head that was mostly a pair of pale, protuberant eyes. It squealed in the moment I pinched it out, and left a curious chemical reek in my nostrils. 
The constable told me that this squalid cellar, which was not much bigger than the room I rented at Mrs. Rolt's, had been the home of some half dozen people, who slept with the oranges and salt herring and the other wares they hawked in the streets. He added that the inhabitants had all scattered, of course, and it was fortunate for me that the landlord had not yet been able to find anyone to set the place straight so that he could rent it again. 
I thought that the imp's malevolence probably had as much to do with the landlord's problem as Coffee Joe's murder. I pointed to the urchins who were watching us through the bars of the little window, and expressed surprise that someone could have been murdered in a room where half a dozen people lived, in the middle of an area so crowded that everyone's business must have been common knowledge. 
"This is a hiding place for every kind of rogue," the constable said. He was a saturnine man, with the weary air of someone who has seen entirely too much human rottenness, and he was not much interested in my business, or the murder. "Most of them are Irish, with no liking of English law. We call it the Rookery; they call it 'Little Dublin,' or 'The Holy Land.' We have no witnesses at all, only stories told by two of our informers. They both say it was a Savage that done it, but can't agree to his particulars. One says that he was black; the other that he was more like one of the indians from the South American jungles. The first claims that all his teeth were filed to points, the other that his teeth were mostly gold. And so on. All we know is that he murdered your man and chased everyone out of this room. Have you found something interesting, sir?" 
I had been turning over flagstones with the tip of my cane. "I notice that there the bloodstains are only on the top sides of these stones," I said, "no matter which way they ended up. It suggests that the excavations were made by the murderer, after he had killed poor Coffee Joe. He must have spent some time at his work." 
"No doubt people were watching at the door and window, and no doubt they saw which way he went when he had finished, but they'll never tell us. Not that it matters, sir. Your man was on the run from the colonies, and this is a murder that saved the time of judge and jury and the hangman." 
The constable needed little encouragement on my part to quit the cellar for the slightly fresher air of the court outside. I vaguely heard him shout at the two urchins, but I was already setting out the saucer I had brought with me, and filling it with brandy with the bottle I had bought in the dining-house where I had lunched. 
The brandy burned with a bright blue flame, and a festive smell that sweetened the fetid air. I sat back and waited, sucking on a stick of barley-sugar, and presently a pale face leaned, as it seemed, out of the shadows. It was gasping like a newly-landed fish, and rivulets of blood poured from the gaping wound in its throat, splashing and smoking away on the floor, as it craned eagerly toward the fumes rising from the saucer of burning brandy. 
"I 'as such a great thirst," it said, over and over, in a wheedling whine. "Just wet my lips a little, mister, and I'll tell you all you want." 
It told me anyway, of course, after I compelled it. Like most revenants, it was much confused, but it took only a few minutes to get its story straight. It seemed that Coffee Joe had made his way back to London as soon as he had completed his three years of hard labour, drawn by the thing he had found in the muck in the Thames Tunnel. After he had returned to London, it had taken him several days and a great deal of drink to pluck up his courage, but at last he befriended one of the men who had a pallet in the cellar, and came back with him, intent on disinterring his prize. The revenant had little memory of the man who had followed and attacked Coffee Joe, would only say that it was a powerful fellow who had frightened off everyone else. 
"He threatened me very badly, but I fooled him, didn't I? I told him it was under the floor." 
"How did he know that you had it?" I said. 
"He said his master had heard the story of what I had found, and had seen that I was touched by it. And it's true, mister. My hand has never been the same since I found it-it has hurt me terribly and given me no little trouble ever since. I should have stayed in the colonies, but it tormented me every night, and only gave me rest when I swore to return." 
There were more pleas for a little drink to dull its pain, and it grew very sulky when I compelled it to speak plainly, and tell me where the thing was hidden. As soon as it gave up its secret, I relieved it of its suffering and found the loose stone in the wall, and the little parcel, wrapped in a filthy scrap of cloth, in the space behind it. 
My right hand began to ache badly and the taste of blood grew thick in my mouth as I unwrapped what Coffee Joe had taken from the Thames Tunnel: 
The two bones of a man's finger, blackened by great age, yet still held together by a scrap of skin. 

· · · · · 

I was following the constable's directions toward Islington when a two-wheeled carriage cut out of the thick traffic and jolted to a halt by the kerb. The driver, a dull-eyed man with an oddly shaped head much too small for his body, stared slackly ahead, taking no notice of the spirited oaths of a carter who had been forced to rein in his horse to avoid a smash. The carriage door sprang open and the passenger leaned forward like a half-opened jack-knife and beckoned to me-it was the white-haired man from the seance, Dr. Pretorius. 
I was young then, and much less cautious than I am now, and I accepted Dr. Pretorius's invitation with the same confident curiosity which had spurred me to attend the seance. Dr. Pretorius pulled sharply on a chain as soon as I had climbed inside the carriage, and it moved off with a sharp jerk that banged the door shut and threw me onto the narrow leather-covered bench facing him. 
"I am delighted to meet you at last, Mr. Carlyle," he said. His accent was cultivated; his tone both mocking and amused. He wore the same black coat and high-collared shirt as at the seance, and a soft, shapeless hat perched on his vigorous mop of white hair. When I asked where we were going, he said, "You have not been long in the city, I believe. Allow me to show you something which will be of great interest to a man such as yourself. It's just a little way beyond what was the valley of the Fleet, within the old wall." 
"I am flattered that you take an interest in me," I said, and it was not entirely untrue. At that moment, I was not afraid of this devilish man; I was eager to learn more of him, and to discover just what he knew of the matter of the dead. That he knew something, I did not doubt at all. 
"It wasn't hard to track you down," he said. "Men like us are rare enough, and growing rarer, but we have a natural affinity." 
"I must assume that the thing in the cellar was yours." 
Dr. Pretorius's smile was both cunning and mischievous. "Very remarkable, wasn't it? I created it directly from seed by principles I discovered many years ago, in another country. I had dreams of populating the world with a new race of creatures made entirely by men, but they were frustrated by the failure of a pupil I thought better than he was. Mrs. Shelley wrote a popular romance which burlesques his downfall-perhaps you have read the revised edition that was recently reprinted? No? Well, no matter. It omitted my contribution to the affair completely, and had altogether too much sensation and not enough science. And besides, that was the past, and now we are at the dawn of a new age, and I have new plans: very powerful plans. 
"Tell me," he said, leaning close, "did you have any luck, in that horrible cellar?" 
I felt a first pang of alarm, and was horribly aware of the fingerbones I had recovered. They seemed to beat like a tell-tale heart in the breast pocket of my jacket, and I had to quash the impulse to put my hand over it, to hide my discovery from Dr. Pretorius's piercing scrutiny. Suppose he had set several imps to keep watch in the cellar, and I had seen only one? Suppose one of the urchins peeking at the window had been in his employ? 
I said, as casually as I could manage, "Is the murder of particular interest to you, Dr. Pretorius, or are you merely interested in it for the sake of sensation?" 
He was not at all put out by this, but sat back, saying, "Very good, very good," as he pulled a flask from his jacket. He drank, shuddered as delicately as a cat, and offered it to me, explaining, "A little gin, to celebrate our meeting. It's my only weakness." 
I declined, and he shrugged. "Were you searching that cellar out of 'interest in sensation,' or could it be that you are in the employ of your new friend?" 
"If I have business with him, that's my business, and his." 
"Not if it interferes with the business of others," Dr. Pretorius said, with sudden sharpness. But then he smiled, and said, "But we should not be arguing, my dear Mr. Carlyle! We are both interested in the same truths. We know things about the world that other men dare only dream about. We know how the world really works-the truth that underlies the petty reality which men like your engineer friend labour to master. They are like ants, building castles from crumbs of sand: mighty fortress to them, but to us mere heaps we can crush in an instant. Yes, I saw how that young man took you up, Mr. Carlyle, and I wish I had spoken to you then, but I confess that I was enjoying the scene you created, and was too slow to follow its creator. A very amusing diversion it was, too, far better than the silly bit of cheap theatre those gypsies put on. That, I must say, was very disappointing, but meeting you is more than enough compensation." 
"You know something of the matter of the dead?" 
"I know much about the matter of life, my friend. More, dare I say, than your poor parents. Oh yes, I know about their experiments into the nature of the human soul, the ghastly business with the resurrection men, and the unfortunate accident that occurred when they tried to reanimate the dead with ghosts. 
"I hope you don't mind me mentioning it," he added, with sly false sweetness. "By the band that you wear, I see that you are still in mourning." 
"As a matter of fact, doctor, I mind very much. It really is none of your business." 
"Oh, but I think it is," Dr. Pretorius said, tapping the side of his nose with a finger. "I mentioned a pupil of mine. He was in the resurrection trade too. He stitched new bodies from old, and infused them with electricity in place of the life force. Not so much different from your parents' work, I think, and it came to an equally bad end. It was almost the death of me, in fact, but I escaped, and learned some valuable lessons, too. Our driver, for instance. Perhaps you noticed him? He has greatly benefitted from my attentions. In his former life he was nothing but a common thief, who thought to break into my establishment one night and steal the day's takings. I caught him, and I made a new man out of him. A little brain surgery, some cranial reconstruction … Ah, here we are." 
The carriage jerked to a halt-its driver was all stop or all go, and nothing in between-and Dr. Pretorius opened the door and sprang out with surprising alacrity. He took my arm when I climbed out after him, and steered me across the pavement to a iron grill set in the base of the wall of a bank. 
"The London Stone," Dr. Pretorius said grandly. "I can see that you are unimpressed, but I think that if you look closely, you'll understand why I brought you here." 
It sat in a niche behind the grill, a blackened, lump of stone about two feet across, quite undistinguished except for the pair of grooves worn in its rounded top. If it had been lying on a piece of waste ground, I would not have troubled it with a second glance, but as I stared at it I felt as if it was opening up like the mouth of a well or shaft that plumbed a dimension I had never before noticed. When Dr. Pretorius pulled me away, the ordinary noise and bustle of the street reasserted itself with the suddenness of an explosion, leaving me so faint that I reeled back against the wall. 
"You see its puissance," Dr. Pretorius said, like a teacher encouraging his best pupil. "I knew you would." 
I could still feel its black power in a corner of my mind, like the onset of a headache, or a thunderstorm. I said, the words coming so hard they might have been the first I spoke after a year of silence, "What is it?" 
"Some say that it is a Roman milestone, perhaps the pivot from which all measurements in the province of Britannia were taken. Others claim that it came from Troy, brought here by the great-grandson of Aeneas, who led the exodus of the defeated Trojans after the Greeks destroyed their city; they would have it that London is the New Troy." 
Dr. Pretorius struck an attitude and declaimed with actorly vibrato, "'And Kings be born of thee, whose dredded might shall aw the World, and Conquer Nations bold,'" then winked at me, and added, "Or perhaps it is no more than a bit of rubble from some forgotten building of old Roman London. It does not really matter what it was. What matters is what men think it is, as I'm sure you'll agree. The Kentish rebel, Jack Cade, rode into the City and declared himself mayor by striking the stone with his sword. Many others have sworn similar oaths upon it." 
"Why have you brought me here?" 
"This stone is on public display, on a public street. Do you not think, in a city as ancient as this, where the streets are raised a good twenty feet above the original ground by the rubble and trash of the ages, that there might be other stones, more puissant, more powerful, hidden away beneath our feet?" 
"If there are such stones, Doctor, I believe that they should stay buried. I certainly understand why this one is caged-not to protect it from the public, but because, like a wild beast, the public must be protected from it." 
"I'm disappointed," Dr. Pretorius said, although he was still smiling his sly, feline smile. "I thought you a man of ambition and vision, like myself. Perhaps it is the shock. Perhaps," he said, offering his flask, "a little gin will help you think more clearly." 
"I can think clearly enough," I said. I was angry, stung by Dr. Pretorius's insinuations about my parents, and my anger made me very reckless. "I think that Coffee Joe was murdered because he had found something you need. I think you flatter me because poor Coffee Joe resisted your questioning, and now you need my help to find what you seek." 
"I do not need your help to look for what I already have," Dr. Pretorius said, and wagged a bony finger in my face when I started to speak. "We are equals, my dear Mr. Carlyle, and we should not conceal anything from each other. The engineer has hired you, I suppose, to rid that ridiculous tunnel of a malign influence. Yes, I know that you went there with him last night. He heard of the murder, realised that the man's boasts of finding something were true, swallowed his considerable pride, and attended the seance. He hoped to ask a question of a ghost, and found you instead. And what, I wonder, have you found?" 
"I won't help you." 
"I could take it from you. I could freeze your blood with one word and take it now." Dr. Pretorius studied me for a moment, then said, "The engineer does not know what he has stumbled upon. It is a far greater matter than removing a hex from a hole in the ground." 
"Nevertheless, he is my client." 
Dr. Pretorius laughed. "You are a stubborn fellow, Carlyle, but not too stubborn, I hope, because I would not like to lose a talent like yours. Such wonders we could do together! When you are ready to talk with me, I can be found at the Museum of Natural Curiosities, on Farringdon Street. It is not far from here-just outside the old walls. Now, you will have to excuse me. Things are progressing very well, and I must be about my business." 
As soon as Dr. Pretorius had climbed into his carriage, the horse bolted as if stung by a bee. Dr. Pretorius waved from the window, and the carriage and its strange cargo was swallowed in the unending stream of traffic. 

· · · · · 

I recovered most of my poise and perhaps half of my strength by consuming two rounds of beef and horseradish sandwiches and a pint of strong coffee in a coffee house, and found my way to Farringdon Street, taking a circumlocutory route to avoid the killing grounds at Smithfield, where the air was still thick with the residue of witch-burning mobs. The street, jammed with slow-moving carts and carriages, ran through a narrow valley; I remembered that Dr. Pretorius had said that we would cross the old course of the Fleet, and supposed that I had discovered it. 
The Museum of Natural Curiosities was a double shop-front, its woodwork painted bright red and the glass of its windows gilded. Boards listed the wonders to be seen within (amongst others, a dog-headed boy, a two-headed sheep, the skeleton of a giant, a genuine mermaid from the Floridean shore, an exquisite miniature ballerina). A large black man stood in the doorway, his muscular arms crossed over the keg of his chest as he scrutinised every passerby. He wore a kind of Arabian Nights costume of loose, buttercup yellow trousers, a broad cloth belt, a deeply slashed pink tunic, and a white turban. The sword sheathed in his belt seemed to be no more than painted wood, but he was of such a size that he would have needed no other weapon than his fists to deal with most troublemakers. I had no doubt that he was the man who had murdered poor Coffee Joe. 
I watched the museum and its muscular guardian from the other side of the busy road, munching on roast hazelnuts purchased from a street vendor, but saw no sign of Dr. Pretorius. At last, I took my chance and crossed the road when the heavy traffic came to a standstill (all around me, hundreds of horses, momentarily released from their work, snorted and tossed their heads), coolly walked past the Museum and its forbidding guard, and entered the tobacconist's next door. For the price of a screw of snuff, I learned that the Museum had been open for just six months, and that the tobacconist, who lived above his shop, was thinking of bringing legal action against the owner because of the construction work that continued day and night, and which more than once had caused his cellars to flood. 
After escaping from the tobacconist's torrent of complaint, I walked north through the brawling streets toward my lodgings, pausing only to donate my screw of snuff to an indigent on a street corner, with the request that he stop torturing his set of bagpipes until I was out of earshot. 

· · · · · 

When I returned to Mrs. Rolt's house, I found on the hall table a folded slip of paper with my name written on it in slanting copperplate. It was a message from Brunel. All arrangements were in hand, and I should meet him at the yard in Rotherhithe at one o'clock tomorrow afternoon "for an unusual perambulation." 
I took supper with Mrs. Rolt and Mr. Rolt and their two daughters, and retired to my room as soon as I could decently disengage myself from the general round of conversation. The encounter with Dr. Pretorius had exhausted me, and I was eager to examine the grisly remnant which had cost Coffee Joe his life. Yet although I studied them long and hard, I could find no power, not so much an imp, in the conjoined stubs of blackened bone, and I could not imagine why Dr. Pretorius needed them, and what they might signify in the matter of the tunnel. 
At last, I wrapped the bones in a clean linen handkerchief, set them on the little table that served as my desk, and made a few notes about my adventures of that day before retiring. 

· · · · · 

I woke the next morning from a terrible dream, drenched in sweat, my heart pounding hard. I tottered to the window and drew in calming drafts of the warm morning air. All around, the ordinary world was getting on with its ordinary business. A blackbird, perched on a fence top with its tail cocked and yellow beak agape, was singing its heart out. Two gardens over, a woman was pinning white sheets to a line. The smell of grilling bacon drifted up from the kitchen window directly below me. The black, smothering mood of the dream faded, and I was able to think about breakfast, and getting dressed. 
I was lacing up my boots when I noticed that the handkerchief had somehow become unwrapped, and that the two fingerbones had fallen to the floor, lying there in their scraps of black skin like the mummy of an exotic caterpillar. 
When we met in the yard, I told Brunel of my discovery of the fingerbones, the encounter with Dr. Pretorius, and the dream. He listened with close attention, absorbing the matter of the interrogation of Coffee Joe's ghost as if it had been a description of some clever bit of lathe work, and asked at the end if he could inspect my prize. I had interred the bones in a tin which had lately contained parma violet pastilles. Brunel stirred them with his forefinger, and said, "You think that this gave you your nightmare of drowning?" 
"Not of drowning, Mr. Brunel; of being drowned. Of being sunk deep in cold, lightless water, with water filling my nose and mouth and lungs, and such a great weight of water pressing down on me so that I could not move." 
"My dreams were of being drowned when the tunnel flooded, instead of escaping," Brunel said, looking sideways at me. An unlit cigar was stuck in his mouth. "Still, it's not so very different. But if your dream was given to you by these little bones, what gave me mine?" 
"In my limited experience of bones, Mr. Brunel, where you find one, you are likely to find others to match." 
Brunel grinned around his cigar and handed the tin back to me. "You think that these little bones came from a body lodged above the tunnel. Well, it's time to look for it, don't you think?" 
"You promised 'an unusual perambulation.' What, precisely-" 
"Let's not spoil the surprise," Brunel said, and took me by the arm and steered me across the yard. 
It was a fine sunny day, and the masts of the ships anchored along the edge of the river were like so many black trees scratching the blue sky above the roofs of the warehouses, as if Birnam Wood had waded into the river to pause and cool its rooty feet before resuming its march on Dunsinane. A wharf stood up to its knees in the low tide. A small boat with some kind of cargo draped in oiled canvas was moored on one side; an ordinary skiff with a man waiting at the oars on the other. As soon as Brunel and I had settled into the skiff, the boatman cast off and with strong strokes hauled us aslant the river's strong race, each dip of the oarblades releasing little packets of noxious stink that blew past us in the hot, heavy breeze. Brunel lit his cigar against the smell; I covered my mouth and nose with the handkerchief which had lately acted as a winding sheet. The bristling hedge of ships along the far bank, and the roofs and steeples rising beyond them, were shrouded in a thickening haze. A steam packet went by, dragging a thick tail of smoke behind it, its paddlewheel threshing up foamy waves that rocked and rerocked our little skiff as they chased each other toward the bank. Brunel grinned when I clutched at the damp wood of my seat, and pointed to a low dark barge anchored a little way off. There was a crane angled up from its midsection, and on the deck below the crane's beak, connected to it by a cradle of slack chains, was a bronze sphere that, with sharp highlights winking from it in the hot sunlight, could have been a bell taken from a cathedral tower. "There's our destination," he said. 
"The barge is moored over the end of the tunnel, I take it." 
"Not at all. The tunnel extends more than fifty feet beyond. But that, so I calculate, is the place it reached when Coffee Joe quit his position. What is it, Mr. Carlyle?" 
The bones had begun to rattle inside their little coffin, which I had tucked in the breast pocket of my jacket. I took out the tin and placed it flat on my palm. As Brunel watched it shiver and shake, I said, "If they can produce bad dreams, I suppose we should not be so astonished that they are also able to move." 
"I don't doubt that they are moving," Brunel said. "The question is, why are they moving?" 
"Perhaps these are animated by a desire to be reunited with their fellows, although I confess that I have never before seen such a thing." 
"They are altogether unique, aren't they? With your permission, Mr. Carlyle, I would like to try a little experiment." 
He had me pinch the tin between thumb and forefinger as, watched by a couple of men on the low deck, the boatman took us parallel to the barge's black, wet side. The tin began to vibrate urgently and noisily when we cleared the bow, and Brunel told the boatman to let the current take us for a moment. The rattling grew less as we drifted backward; increased again as we rowed forward. Brunel took a sighting of either shore to mark the spot, and told the boatman to make for the ladder. 
After we climbed aboard, Brunel introduced me to the captain and then strutted over to the gleaming bell (his reflection swimming up to its shining surface to meet him) and briskly rapped it with his knuckles. "I borrowed it from the West India Dock Company, Mr. Carlyle. Are you much troubled by enclosed spaces, by the by? I clean forgot to ask." 
"No more than any other man," I said. "What does a bell have to do with dredging up-" 
"Dredging? No, sir, that's far too chancy, as I think someone else has discovered. We're going to dig it up." 
Brunel left me to wonder about that as he gave the captain instructions, pointing to the spot of water a few dozen yards off the bow of the barge where the fingerbones had become most agitated. The barge blew a cloud of black smoke from its tall chimney, raised its anchor, and moved against the current and dropped anchor again, all in a minute. Brunel satisfied himself as to the spot, and then two men started up the steam engine of the crane. Chains rattled as they were wound on a great drum, the frame of the barge creaked as the bronze bell was lifted a yard above the deck, and I tardily understood Brunel's audacious plan. 
A narrow wooden footboard ran around the inside of the bell, a foot or so above the rim, and there were leather straps rivetted to the curved metal wall. Hatless and in our shirtsleeves, accompanied by a gruff labourer armed with a grappling hook and a wooden shovel, Brunel and I clung to these straps as the bell was swung out over the swiftly-running brown water and lowered into it. 
My ears sang and popped as we descended. The level of the circle of water beneath our boots crept toward the footboard, and Brunel explained that the eagerness of the air to escape the bell almost precisely countered the eagerness of the water to enter, but air was compressible while water was not. 
"I used this apparatus before," he said, "to inspect the aftereffects of the first inundation. I was able to step from the footboard onto the corner of number twelve frame of the tunnelling shield: a quite remarkable experience. What do the bones say? Are we close?" 
The tin was tucked into the pocket of my trousers, and the fingerbones inside it were rattling like a demented castanet. "They are very excited," I said. 
The bell grounded with a solid thump. Beneath the rim of the footboard, a circle of black mud and gravel lay under about six inches of cloudy water. Brunel, the labourer and I scoured it with grappling hooks until, red-faced, our eyes starting from their sockets, we were forced to pull the communicating string, and were lifted to the surface and a brief respite in the fresh air before being submerged again. 
And so it went for half a dozen attempts, until at last the labourer hooked the end of a long black bone. Brunel stepped down from the footboard and delved in the silt and pulled up the bone. I took it from him (it was a humerus), feeling the tin vibrate with a regular tarantella. We went up for air and came straight back down, and Brunel and the labourer began to excavate the two feet or so of silt above the brick arch of the tunnel, and at last uncovered a bundle as long as a man, wrapped in something like the casing of a giant beetle, black and slippery and stinking badly. 
It took all three of us to haul it onto the footboard, and when we were done we were dizzy and gasping for breath. Brunel pulled the string, four long strong tugs, and we rose up for the last time and were swung above the deck of the barge; and never more grateful was I to feel sunlight on my face as I ducked under the dripping edge of the bell. 
Brunel and I unwrapped the body on a bench in the long shed. The wrapping had once been the hide of some large animal; a few patches of coarse hairs still clung to it here and there. Although it had been cured by centuries in the river mud, it stank horribly, and was as stiff and brittle as if turned to wood. Brunel used his pocket knife to cut away the final leaf, and a slough of black mud slid out, thick as porridge, to reveal a human skeleton. It was missing its right arm, which might have fallen away through a ragged tear in the shroud, and its skull. 
Brunel looked at me across the rack of wet bones. "How is your tin?" 
"Curiously quiet." 
Brunel clapped his hands together in delight. "Then I think we have our prize. The question is, just what do we have?" 
"I cannot raise the dead, Mr. Brunel, and there's no ghost or imp associated with these bones. It's a skeleton, no more and no less, of a man who died a long while ago." 
"I know little about bones," Brunel said, "but I don't think that ordinary skeletons engender an anxious vitality to one of their stray components. And then there is the matter of the missing head." 
"It is a puzzle." 
"For every puzzle there is a practical solution. Even in the matters in which you are expert, I hope. We have a skeleton here, and a bit of bone that dances a jig, it is so anxious to be reunited with its fellows. We have the bad dreams of myself and Coffee Joe, and at least half a dozen others who were intimate with this site. We have the water which grew so agitated yesterday, and which exerted a certain power over you, Mr. Carlyle." 
"And which also tasted of blood." 
Brunel levelled his bright gaze at me. "And blood, I might think, being a vital fluid, might have some importance in these occult matters." 
"It is not a matter of the occult, Mr. Brunel. But I do agree that we may have stumbled on something deeper than ordinary ghosts. And there is one more fact we must take into account. This was no ordinary death." 
I showed Brunel where the seventh cervical vertebra had been severed by some very sharp blade. "It was a downward stroke," I said, "to judge by the angle of the cut." 
"Signifying?" 
"He was kneeling, and the man who beheaded him struck from above." 
"As in an execution." 
"Precisely." 
We examined the bones closely. It was the skeleton of someone who had stood well over six feet in life. We found a ring of blackened metal loose on the bone of the forefinger of the left hand; a nick with the blade of Brunel's pocketknife showed that it was gold, and when he polished it with a scrap of cloth, he revealed a name inscribed on the inner face: Ulpius Silvanus. We found the point of an arrow buried in an old, healed wound in the right thigh bone. We found a much-corroded buckle, decorated with a relief of a man wearing a kind of stocking cap and riding a bull. 
Ulpius Silvanus had been a tall, strongly-built man who, judging by the arrow-wound, might once have been a soldier. He had been beheaded, but his corpse had not been looted, and he had been wrapped in a shroud of cowhide and tipped into the river, where the tides had at last washed his remains to the spot which, centuries later, the progress of Brunel's tunnel had disturbed. His arm had become detached from the rest of his bones, and two fingerbones had washed into the tunnel through one of the innumerable small seeps at the working face. Coffee Joe had taken it, perhaps as a lucky piece, and caused all the trouble that had followed. Many questions remained, not least of which why the man had been executed, and when. The name inscribed on the ring suggested the Roman era, and Brunel said that he would call on the expertise of a curator at the British Museum, where many of the finds fallen into the excavations had been lodged. 
I felt a profound satisfaction. Not only had I taken on my first client, but I had solved the case within two days. I told Brunel that I hoped that now the curse had been lifted the tunnel would soon be completed, so that I would be able to walk its length from one side of the Thames to the other, and assured him of my full attention should there be any problem concerning the interment of the remains. 
Brunel solemnly shook his head from side to side, just once. "It is not the end of the matter," he said. "You have forgotten Dr. Pretorius." 
"Not at all. The man is dangerous, certainly, and although I have no proof that would satisfy the police I am convinced that he was responsible for the murder of Coffee Joe. But he is a mountebank, Mr. Brunel, no better than the gypsy girl." 
"Nevertheless, he found Coffee Joe, and he found you, too." 
"I suppose there was the imp," I said reluctantly, and had to explain to Brunel what Dr. Pretorius had left behind in the cellar where Coffee Joe had been murdered. 
"He is not entirely a mountebank, then," Brunel said. 
"I suppose not. What do you propose to do now?" 
"I have strong evidence that someone else has been searching for these bones," Brunel said. "I would very much like you to hear it, Mr. Carlyle, and give me your opinion." 

· · · · · 

We covered the bones of poor Ulpius Silvanus with an oilcloth, locked up the shed, and walked east along Rotherhithe Street, between the river and the Surrey Docks, to a little tavern by the name of The Porter's Rest. Approached from an undistinguished back street, and entered through a tiny court, it revealed itself to be hanging half above the river, jammed between the higgledy-piggedly buildings on either side like some ancient galleon at its last anchorage. The timbers framing the plaster walls of the tap and parlor were black oak, and not one met its fellows at anything resembling a right angle, so that the little room seemed to be leaning in the teeth of a gale. There was a bench under the mullioned window and two settles fitted with faded red bolsters faced each other on either side of a fireplace of rough stones. A crooked door to one side of the fireplace let into a dark, crooked snug, where two crooked ancients were hunched over a ladder of dominoes on a crooked table, and a sliding window at the far end of the room opened onto the bar of the establishment, where a stout old man with a polished pate sat on a high-seated chair, the guardian of the row of beer-pulls set at the shelf by the window. He wore a pair of spectacles on the very tip of his nose, and was perusing a newspaper held only a few inches from his face, moving it, and not his eyes, as he read up and down its close-printed columns. 
Brunel greeted the old man with no little respect, and asked after Jake. The man carefully folded the newspaper in half and laid it on the scrubbed pine table which took up most of the space of his little kingdom, looked at Brunel over the top of his spectacles, and told him that he would send the pot-boy for him directly, looked at me, looked at Brunel again, and asked what refreshment we would require while we waited. 
Brunel said, "We'll take two glasses of the Absolutely Stunning, Mr. Welch, and I hope you'll join us in a little something." 
The old man allowed that it was a little early for him, but he'd gladly set aside something to go with his supper, drew into pewter tankards two pints of dark ale, and said, as he handed them through the window, "Your company is always welcome here, Mr. Brunel, but I'm sorry that you should choose to ask in a rogue like Jake Mullins." 
"I can promise you there'll be no trouble, Mr. Welch," Brunel said, turning his hat around in his nimble white fingers like an admonished schoolboy. 
"It's not trouble I'm worried about," the old man said. "If it was trouble I worried about, I would have closed up the Porter's as soon as I inherited the care of it from my late father. Should trouble stick its nose around the door of my establishment, I deal with it sharply, so that it knows that it has no place here." Here, he gave me a significant look. "My concern is that your invitation will give Jake Mullins the idea that the Porter's is a house he can use regular, and that ain't the case at all." 
"I could always find him in his own haunt," Brunel said, with a glance and a smile at me. "The Black Bear, I believe, is his house of choice." 
"It's his house of last chance, in my considered opinion, and I wouldn't think of a gentleman such as yourself, and your friend here, troubling to go there." 
The old man gave me another significant look, and Brunel said, "I have been tardy in my introductions. My friend is Mr. Carlyle, late of Edinburgh." 
"I can't say I know him," Mr. Welch said, "but he's welcome enough, I'm sure. Jake Mullins is another matter. I'll be glad if you make it clear to him that a single pint is all he's due here, today and tomorrow, and any other day for that matter." 
Brunel humbly assented to the condition and paid the price of that single pint in advance, and I bought a wedge of cheese and bread to fortify myself after my underwater adventure. We made ourselves comfortable at the window overlooking the river, its broad flood as red as blood in the lingering light of the summer sunset. Swallows and bats were swooping to and fro as they chased insects just above calm surface of the reach of water between the bank and a file of ships anchored stern to bow. 
Brunel told me that Mr. Welch had run the establishment for more than forty years, and knew everything worth knowing about any business along this part of the river. "It was he who sent a message about what was seen about the river above my tunnel," he said, "and told me how to contact the man who saw it." 
"And what was it he saw?" 
"I think you should hear that from him," Brunel said, looking past me and half-rising, "for here he is now." 
I turned, and saw not a man at all, but an indistinct figure as hung with ghosts and imps as a battleship on review is hung with flags. The imps clung to his hair and shoulders like a congregation of tiny, spiky black monkeys; the ghosts swirled about him like rags of fog, their filmy faces set with despair and desperation. Several of the strongest glimpsed me, and set up such a fearsome agitation that the entire company promptly exploded all around the room. I jumped up in a hot panic, knocking over my pint-pot, dispatched them all, and fell back into my seat in a swoon as Brunel crossed the room in three strides and grabbed hold of the collar of the grizzled wretch who had been their host. 

· · · · · 

While the pot-boy mopped up spilled beer, I sipped at the balloon of brandy Brunel had thrust into my hands, and felt my blood begin to circulate again. Brunel was placating Mr. Welch, and the man I had so summarily freed of his burden sat hunched on a stool, telling the frothy head of his pint of Absolutely Stunning that he felt as if all his bones had been taken out of him, that he might have had a stroke or a conniption fit, and that he should be attended to by a doctor at once, before he gave his soul up to the Other Side. 
Brunel, when he was done with Mr. Welch (or rather, when that good man was done with him), sat between us and looked from one to the other, and said, "I suppose you had better tell me what happened, Mr. Carlyle, because I don't believe that Jake here quite knows where he is." 
"I know," the man said, "that I needs a doctor." 
He was a man in his late thirties, his face seamed and sunburnt, a cap set back on the grey, greasy curls of his head, the knot of the red handkerchief slung around his neck under his vigorous grey beard. His shirt was half-unbuttoned and its sleeves rolled up his muscular brown arms, and his corduroy trousers were so stiff with mud that they could have stood by themselves. 
"You'll make do with this for now," Brunel said, handing him a wedge of cheese. 
The man looked at it, sniffed it, and finally gnawed at it, looking sideways at me as if afraid that I would take it from him. Brunel was looking at me too. 
"I removed his burden," I said. "I can assure you that he will suffer no ill effects-quite the reverse, in fact." 
Brunel nodded, and said that he thought he understood. 
The man, Jake Mullins, looked up from his gnawing, and said that he didn't understand it at all. After some prompting from Brunel, he allowed that perhaps a doctor wasn't required, at least not at the instant, and the young engineer told me that Jake Mullins was a fisher of men, and so was well matched to me, a fisher of an altogether different kind of intelligence. 
"I wouldn't call 'em intelligent," Jake Mullins said. "Not when I finds 'em, anyways." 
He seemed much calmer now, and there was purpose in his gaze. He pressed a fist to the small of his back and straightened on his stool with a sigh, and took up his pint pot and drank a good deal of it down in a single draft, wiping his lips and beard with his forearm and sighing again, like a man sinking into the comforts of domesticity after a long day's work. 
Mr. Welch, leaning at his little window, took note of that sigh, and said sharply, "Don't you make yourself at home, Jake Mullins, and don't think you'll get more than that pint out of me, either. Whether your business is long or short with these gentlemen, that's all you'll get, so sip it with care." 
"Don't you worry," Jake Mullins said cheerfully. "I'm not going to cause you any trouble." 
Two regular customers came in just then, greeting Mr. Welch by name, and saving him from making a reply. 
Jake Mullins took another (much smaller) draft of beer, and said, "He's all right, is Welchy, except that he is a bit too particular about who deserves his custom. It's my trade that he doesn't like, so it's peculiar, ain't it, that my trade brings me here to talk with you, Mr. Brunel. And with your friend, whoever he may be." 
I introduced myself and shook Jake Mullins's hand, which was as hard as any length of black oak in the room. 
"A Scottish gentleman," he said. "Perhaps you're a doctor-I know they're famous for their surgeons-which is why you're able to tell me that I'll be 'quite all right.' " 
"I see a man who has been labouring under a burden," I said. "And I believe that he is beginning to realise that that burden has been lifted from him." 
"Then perhaps you're a clergyman," Jake Mullins said. "You dress like one, saving the backwards collar. If not a clergyman, perhaps a missionary, come to save us poor benighted river rats." 
"A clergyman is closer to the mark than a doctor," I said. 
"Mr. Carlyle has volunteered to advise me," Brunel said, and produced with a flourish a half sovereign from one of the pockets of his waistcoat. "This is what was agreed, I think: twice your inquest money. And now, if you please, Mr. Mullins, you will tell your story." 
Jake Mullins took the coin, rubbed it with a thumb, tasted it, rubbed it again, and shoved it into the pocket of his breeches. 
"I'm obliged," he said. "There isn't much to tell, but I'm sure you'll think it worth it." 
"It was just three nights ago, I believe," Brunel said, with a fair amount of impatience. 
"It was. I was running along the Surrey shore in my little boat, past the wharf that used to service your diggings, when I seen it. A little boat like mine, standing seventy or eighty yards from the shore. I thought at first that Bullhead Harvey was in luck again. I was about to hail him, but then the moon peeped out from behind a cloud, and I saw two things. First, that Bullhead wasn't alone, and second, the man I took for Bullhead weren't him at all, but a man considerably thinner, with a bush, as it looked like, of white hair. The white-haired fellow was in the stern of the boat watching the other man work, and the other man was not someone I cared to make acquaintance of on the river; or any other place, for that matter." 
"He was a big man," I said, "with dark skin." 
Brunel shot me a glance, and Jake Mullins said, "If you know him, then you know why I hung back. Almost too big for the boat, he was, and either a Nubian or a lascar, with a shaved head, and a neck quite as thick. He'd been leaning over the water when I first spied the boat, but then he stood up, hauling on a kind of chain mounted with hooks. The white-haired gent was talking to him in some queer argot, sounding pretty impatient, and holding on to the thwarts because the boat was rocking from side to side, fit to capsize. 
"Presently, all of the chain was in, and the big man took up the anchor and let the boat drift a ways. The white-haired gent leaned over the side, making little passes of his hands, and I thought I saw a blue light burning. It was as if he had set fire to something, except that the flames burned upside down, if you see what I mean-under the water, instead of on it. There was mist or smoke above, swirling about as if trying to make a shape, before it blew away. This operation was repeated two or three times, and at last the white-haired gent hissed some instruction to the big man, who cast the coils of chain over the side again, and let the boat drift again before hauling in the chain-again with no luck, which made the white-haired gent pretty unhappy, I think." 
"You had plenty of time to see all this," Brunel said. 
"I was safely in the shadow of a jetty, for it's around about obstructions to the river's currents that I most often find what I'm looking for, and I sat still and watched a good while. Not daring to move, you see, in case they spotted me. I'm a strong rower, but that big man, he could have out-pulled a frigate, to my reckoning. So all I could do was watch, until after an hour the white-haired gent slumped back, and the big man took up the sculls and rowed off." 
Brunel said, "In what direction?" 
"He was rowing against the current, and going faster than any boat I've ever seen. If I had made a run for it, he would have caught me before I'd gone more than a few lengths." Jake Mullins drained his pint. "Well, that's my tale, gents, and I hope it was worth your time and your money." 

· · · · · 

As we walked back through the dusky street toward the yard, Brunel said thoughtfully, "Where do they go?" 
I understood him at once. "I do not send them anywhere. I simply give them rest." 
"You have no misgivings about what you do? Some would say that it is very like murder." 
"They are not souls, Mr. Brunel; if they were, it would not be my place to send them on. What people commonly call ghosts are not souls with some unfinished business that delays their passing over, but shells cast off at moments of intense, concentrated emotion. It is true that many are cast off at death, but not all who die cast off a ghost, and not all ghosts are cast off by the dying. Most are not long-lived, and almost all are damaged or deformed representations of the people who produce them. There are very few with whom you could hold a sensible conversation, and even fewer which would not feel relief at the moment of dissolution. They are poor frightened creatures that cling to a familiar place or a familiar person. Most often they haunt the person or the body of the person who cast them off, and those last often become attached to whoever finds that body. I believe that I am able to make a guess at Mr. Jake Mullins's occupation, even without your mention of 'inquest money.' " 
"He is a river finder. He and his kind dredge for all kinds of things by day—coal, animal bones, pieces of metal. They ferry contraband from one place to another, too, usually items of cargo from ships waiting to be unloaded." 
"But at night, Mr. Mullins and his fellows look for bodies of the drowned." 
"He gets the reward, if there is one, and in any case five shillings from the police. Was he much … inhabited?" 
"I should say that he has been pretty successful in his searches." 
"I should have warned you. I did not think." 
"None of them were harmful. They were mostly pathetic scraps. It was the number that astonished me." 
Brunel laughed. "A few days ago, I would have thought myself mad if I had found myself in the middle of a conversation like this." 
"A few days ago, you would not have considered attending a seance." 
"Perhaps I am mad," Brunel said thoughtfully. "The dreams were certainly bad enough to be the dreams of a mad man. I suppose it would be too simple to think that I am haunted by the ghost of Ulpius Silvanus?" 
"There was no ghost that I could detect. Of course, there are lesser creatures than ghosts. Imps of delirium and madness, and the like …" 
Brunel looked at me from beneath the brim of his stovepipe hat. "What is wrong, Carlyle?" 
"I have been a fool. There are creatures lesser than ghosts, and there are greater creatures, too. Something has been awakened, I think. Something very old, and once possessed of great power. Think, Mr. Brunel. What kind of stone commonly becomes the focus of human desires?" 
Brunel had the quickest mind of any man I have ever met. After only a moment, he said, "You think that Dr. Pretorius is searching for an altar." 
"I do indeed. And because the remains we found are almost certainly that of a Roman soldier, I believe that it is an altar that was dedicated to some pagan god long before Christianity enlightened these shores. Pretorius spoke of stones under the city. And is the city not built, layer upon layer, upon its own past, like one of the coral reefs in the warmer seas of the Antipodes?" 
"But what use would Pretorius have for an ancient altar? And what does the skeleton have to do with it? I confess that I find this business baffling. The more we know, the less clear it becomes." 
"I believe that the poor man whose bones we found was sacrificed on the stone Pretorius seeks. His head was chopped off, and no doubt his blood was used in some dreadful rite. Just as the fingerbones led us to the skeleton, so the skeleton could lead to the stone. It is, after all, still missing its skull." 
"But did not Pretorius say, as a parting shot, that he had already found—" 
Brunel broke off because the old fellow who guarded the gate of the yard at night was running down the narrow street toward us, slinging his rattle around his head and yelling murder. 

· · · · · 

The door of the shed had been smashed to kindling; only a few splinters still clung to its bent hinges. Brunel quickly ascertained that nothing had been taken but the skeleton, and closely questioned the watchman before giving him an address and instructing him to tell someone called Withers to find the Dowling brothers and bring them straight here within the half hour. 
As the watchman hurried off, I asked Brunel what he was planning. He put a match to a lantern, closed the glass on the yellow flame, and said, as much to himself as to me, "The lock of the gate is untouched, so it's quite plain how they came here, and how they left with their prize," and strode off through heaps of construction material toward the riverside edge of the yard. 
I caught up with him on the wharf, where the boat with the canvas-covered load rocked on the greasy swell. I said, picking up from his absent-minded remark, "Pretorius saw me enter the tunnel with you. I should have guessed his vantage point after hearing Jake Mullins's tale." 
"We always come back to the river," Brunel said. He gave me the lantern and climbed down into the boat and began to undo the rope which lashed the canvas over what was soon revealed to be some kind of boiler: a pair of upright, conjoined cylinders cast from heavy, dull metal. The summer twilight had quite faded from the sky now, and lamps on moored ships and along the far side of the river were twinkling in the dusky blue. 
Brunel began to fold up the canvas. "There's no question that he has some need of those bones," he said. "He tried to find them and failed, and then waited for us to haul them up. I am grievously at fault, Carlyle. I should have had the bones taken to a safer place." 
"The Tower might have done it," I said, "but anywhere else may not have withstood Dr. Pretorius's determination. Your watchman was lucky that the theft was accomplished before he started his shift; we already know that Pretorius will murder to get what he wants." 
Brunel looked up at me. "I am determined to see this affair through to the end, and quickly. I would be grateful of your help, but I will understand if you feel that you have discharged your obligation." 
"Would it not be better to go to the police?" 
"What would I tell the police? The truth is too fantastic, and anything less would not stir them to any great haste. Yet speed is of the essence now that Pretorius has his prize. He seemed very anxious to get hold of those bones, did he not? I do not think that he will waste time, now he has them." 
"Do you propose that we break into his museum, then?" 
"That's what he wants us to do. Or at least, that's what he wants you to do. Why else would he have been so careful to tell you where it was? I think he needs you as much as the bones, Mr. Carlyle, and I also think that his choice of the location of his establishment was quite deliberate. It must be somewhere above the grave of this famous stone, for his neighbour mentioned the noise of construction work, which was no doubt the noise of excavation work." 
"Dr. Pretorius has been digging down toward the place where the stone is buried." 
"Exactly. And that is his Achille's Heel. Ah, here they are at last." 
An eager young man in a brown suit, with a bowler hat perched on red curls, was leading two labourers down the wharf. The red-haired man, Roger Withers, was Brunel's assistant in his gaz experiments; the labourers, Thomas and William Dowling, were from the corps d'élite of men who had worked in the frames of the tunnelling shield. Brunel climbed out of the boat and briefly told them what had been stolen from him, and why he thought it important that he get it back. He introduced me as an antiquarian, made no mention of the supernatural part of the story, and concluded by saying that this was dangerous work, and if anyone wanted to jack now he'd think no worse of him. 
Thomas Dowling, his vigorous black hair pulled back in a sailor's pigtail, said that it couldn't be worse than working the shield; his brother, a stocky man with a broad, ruddy face framed by muttonchop whiskers, added that nothing could be worse than that. I saw that these rough, uneducated men had a deep respect for Brunel, and would have made a good fist of digging to the centre of the earth if he had proposed it. 
"We'll use the Lady Sophia," Brunel told Withers. "Have Thomas and William fetch carbonate of ammonia and sulphuric acid, and let them break out tools they feel most comfortable using. I'll prime her, and if you're not back in five minutes I'll be gone without you. Oh, and bring my pistol, and a bottle of brandy." 
As Withers and the two labourers dashed toward the shed, Brunel clambered back into the stern of the boat and began tinkering with the valves and levers of its curious boiler. There was a sharp, distinct chemical smell, and water gurgled through copper pipes that groaned and cracked as they took up their burden. 
"I must suppose," I said, after I had climbed down, "that this is one of your gaz engines." 
"It is the only gaz engine we have," Brunel said, laying a hand on its pipes. "No doubt you have noticed that it has two condensers. One is warmed by circulation of hot water, and the other is cooled by passing cold water through its tubes. I am running the engine on a closed, inefficient cycle to establish that important differential. At full power, gas expands in the heated condenser and is held in its condensed state in the other, giving a difference of some thirty-five atmospheres. That provides the motive force to drive a longitudinal paddlewheel beneath the stern. If we could but scale it up, we could get a man-of-war up to twenty knots." 
"As it is," Withers said, appearing at the edge of the wharf above our heads, "it's a miracle we haven't blown ourselves to kingdom come, and most of Rotherhithe with us. Here are the carboys, Mr. Brunel. I reckon we're about as ready as we'll ever be." 
"And my pistol?" 
"I have it here, Mr. Brunel. May I say that I am not happy to bring it along." 
"We may need the advantage of a little surprise," Brunel said. "Get everything aboard, Mr. Withers, as quickly as you can." 
The carboys, cradled in wicker baskets packed with straw, were carefully lowered to the boat. Brunel siphoned heavy, oily acid from one, while Withers scooped gritty white powder from the other into a hopper. The two brothers settled in the bow, packed in tight with an armoury of picks and crowbars, and a long-shanked maul. The pipe-bound double cylinder of the gaz engine began to emit an urgent rattle, and a high-pitched whistle that quickly climbed beyond the range of human hearing. A red needle moved by distinct jerks across the calibrated face of a pressure valve. The oiled brass and steel elbow of the drive-shaft crank lifted and jammed; Brunel whacked it smartly with a spanner and it began to pump smoothly up and down. He took a cigar from a waistcoat pocket and lit it from the lamp, watched the trembling needle creep toward zenith, and at last declared that we were ready to go. 
Thomas Dowling cast off at the bow, and Withers cast off at the stern. The little boat thumped against the pilings of the wharf, and then Brunel engaged the drive-shaft and the boat shook itself and shot forward into the main current of the river. 
I shall always remember that short voyage upriver. Driven by the gaz engine, the brave little boat cut a fast and sure path against the current. Waves stood at right angles on either side of its bow, and a wide foamy wake beaten by the paddlewheel spread behind, glimmering on the river's black flood. Brunel stood with his cigar jammed in the middle of a broad grin, one hand clapped to the brim of his stovepipe hat, the other on the wheel which was connected by a jointed shaft to the rudder. Darkness was thickening in the air, and long constellations of lights twinkled on either side of us. We passed through the central arch of the five white stone arches of London Bridge, passed beneath the great central span of Southwark Bridge's great ironwork causeway, and overtook a string of barges, quite startling the lighterman at the tiller, who stood up and shouted and waved his cap at us as we sped past. The necklace of gas lights strung along Blackfriars Bridge quickly drew near. At Brunel's instructions, Withers opened a valve, exhausting gas pressure from the condensing cylinders in a series of sharp retorts, and the Lady Sophia's speed dropped to less than a knot. 
We cut in close to the embankment, puttered past two paddlewheel boats at their moorings, and turned into a wide recess in the slimy stone wall of the embankment, with the bridge's first arch looming high above us and a great iron grating ahead, half-submerged in the slop of the river. 
The two labourers grappled us tight to this portcullis. A dank fetid breeze blew from the darkness beyond it. I could hear, on the road thirty feet above, the sound of horses's hooves and the clatter of cart wheels, and snatches of conversation that rose for a moment above the dull roar of the city. My heart was beating in my throat. I had the strange notion that at any moment a policeman would lean over the wall, and raise hue and cry. 
Brunel directed the light of a lantern over the ironwork. His face was flushed with exhilaration, his gaze sharp. He pointed to a joint, and William Dowling applied the tip of his pick and heaved smartly upward. A whole section of the iron grid swung forward, and Brunel and the labourers lifted it above their heads and Withers lashed it tight. 
Brunel wiped his hands with a bit of oily cloth and said, "My guess is that this is how Pretorius came and went. He cut this through, bolted on hinges, and wired the whole shut beneath the waterline. You'll notice the cuts are fresh, Mr. Carlyle, and not yet rusted over." 
William Dowling was leaning over the side, probing the water with his pick. He reported that he thought we had enough clearance, and we grabbed hold of the sides of the opening and hauled our little boat through. As soon as we had passed beyond the grating, I felt an agitation in my breast pocket. It was the fingerbones, rattling inside their tin. Brunel looked at me when I took it out, his face a pale smear in the gloom, and said, "We must be on the right track." 
"Where does this lead?" 
"To Hampstead, eventually," Brunel said. "This is the Fleet River, although it is more sewer than river now. Break out the brandy, Mr. Withers. We'll all have a nip to hearten us before we go on." 
The brandy bottle was passed around, and we all took our nip, and wet our handkerchiefs and tied them over our noses and mouths against the stench. Adjustments were made to the gaz engine, and we puttered forward at walking pace. Thomas Dowling stood at the bow and held up a lantern, illuminating slimy brick walls that curved up on either side to a ceiling a good thirty feet overhead, heavy stone arches, and a kind of quay or raised path to our left. Water gushed from side channels cut at different heights in the walls, and dripped from the arched ceiling, where a forest of white stalactites clung. The stench thickened, palpable in the black air. The water was flecked with islands of filthy foam. The bloated carcass of a dog bumped against the side of the boat, dipped and whirled, and waltzed away. 
Brunel told me that this stygian channel had once been the tidal inlet of a tributary of the Thames which rose in Hampstead and flowed south through Camden and King's Cross. It had marked the western boundary of the city in Roman times—the line of the old wall was to our right. The lower reach, through which we were passing, had been widened and deepened after the Great Fire of London to make a canal with wharves thirty feet wide on either side, but it had quickly fallen into disuse, and a hundred years ago the river between Holborn and Fleet Bridges had been arched over and Fleet Market built on top. The rest of the lower reach had been channelled underground thirty years later, and only a few years ago Fleet Market had been moved, Farringdon Street had been laid out, and the buried river had become no more than a main channel for the area's sewer system. So the living become transmuted and diminish when translated to the realm of the dead, and yet still persist. 
We passed between great stone bulwarks: the remains, according to Brunel, of the footings of Fleet Bridge. Farringdon Street was now directly above us. I was quite unable to match our underground thoroughfare with the living street thirty feet above our heads, but as we passed a channel cut through the high kerb on our left, the bones began to rattle even more furiously in their tin. Brunel swung the bow of the Lady Sophia about, and asked the two labourers to check the depth of the channel. 
"There's a breeze blowing out of it," Withers said. 
"I can feel it too," Brunel said. "What do you feel, Mr. Carlyle?" 
"A certain oppression, from the close atmosphere." 
"But nothing else?" 
"It is curious. This is a very ancient place, and yet—" 
William Dowling, who had been leaning out at the bow, sinking his pick here and there in the water, suddenly reared back with a cry. "I saw a face," he said. "Looking up at me out of the water." 
"You saw a reflection of this lantern light," his brother said. "Don't mind him, Mr. Brunel. He had a little more than a nip of your fine brandy." 
"It was a man pale as snow," William Dowling said. "Very handsome and very horrible at the same time." 
"Not your own reflection then," his brother said, "unless you were mistaken about the handsome part." 
I insisted on looking, but saw only rippling lines of lantern light moving to and fro like yellow water snakes over the black surface of the thick current. Thomas Dowling retrieved his brother's pick, the handle of which stood up from the surface like the hilt of Excalibur, and reported that there was a good three feet of draft. 
"We'll push on, boys," Brunel said, and opened the throttle of the gaz engine. The boat glided through the channel into the arch of the low tunnel beyond. The dripping bricks of the ceiling were only five or six feet above the water, and we had to crouch low. Once, a pipe on top of the gaz engine snagged on something, but the boat shuddered and scraped free. Then the echo of the beat of its drive shaft dropped away, and cooler, slightly fresher air blew in our faces. Thomas Dowling raised his lantern above his head, and Withers held up another; by their double light I saw that we had entered a wide lake under a high ceiling of fan vaulting—the flooded cellar of some ancient building long buried by the accretion of centuries. A rushing stream dropped in a fall of white foam from a narrow channel at the far end, and there was a bank of tumbled stones and clay along the left-hand side. A rowing boat was tied up at the foot of a rough wooden staircase that dropped down to this narrow shore from a ragged opening in the ceiling. 
As Brunel steered toward this, the fingerbones beat so strongly in their tin that it jumped from my grasp and fell into the puddle of water at my feet. As I bent to retrieve it, a breeze got up out of the darkness, and the boat began to rock. Little waves ran across the width of the lake and broke in white water on the stones of the banked shore. Spray flew up and dissolved into a thickening mist that rolled over the unrestful water. Brunel looked at me, one eyebrow raised, and I told him that as in the tunnel it was a phenomenon with no cause I could discern. 
The bow of the boat bumped against the shore, and the two labourers sprang out, thigh deep in swirling mist, and made us fast. I drew the blade from my cane and clambered out after Brunel, who told Withers to stay with the boat and keep the engine pressured before leading the Dowling brothers and me up the rickety stair. 
The bones tick-tick-tickedin the tin, matching the pulse in the base of my throat. We climbed out into a clammy, stone-floored basement, and something toad-like stirred above the door on the far side. I dismissed it in a moment, but before I could raise my own warning the door burst open and half a dozen men crowded through, all of them with shrunken, misshapen heads, all of them armed with pistols. 
Dr. Pretorius stepped into the room behind them, his smile triumphant, and bid us welcome. 

· · · · · 

My cane was taken from me, William and Thomas Dowling were relieved of their pick and crowbar, and Brunel of his pistol and pocket-knife. Dr. Pretorius thrust a pale hand toward me, and I gave him the tin containing the fingerbones. He held it to his ear for a moment, and said, "Is this what led you to the remains of Ulpius Silvanus?" 
"Where are his bones?" I said. "And for that matter, who is he, and what do you want with him?" 
"All will become clear soon," Dr. Pretorius said, tapping the side of his nose. 
The Dowling brothers were tied up and left in the care of two of the shrunken-headed men; Brunel and I were herded back down the stair. Withers was waiting for us at the bottom, sitting on the ground with his hands clasped on his head, the giant savage in his Arabian Nights finery standing watch over him, a pistol in each fist. 
"Bring him along," Dr. Pretorius said. "We may be in need of fresh blood." As we picked our way along a narrow path beaten through the rubble, he told me, "It has all worked out very nicely. You saved me the trouble of bringing up the bones, and then you delivered yourself into my hands. There is still time to recant, by the way. Come in with me now, and your reward will be of this world, and not the next. We will do such things as men have only dreamed of." 
"I believe you have already had my answer," I said. 
"You'll help me anyway," Dr. Pretorius said, "but it would be so much more convenient, and I would be far more forgiving of your friends' trespasses, if you were to give your help freely. Through here, if you please." 
A low, irregular opening had been hacked into the tightly mortared stones of the wall at the far end of the lake. Menaced by the pistols of Dr. Pretorius's servants, Brunel, Withers and I scrambled through a passage driven through the earth to a low-ceilinged, stone-floored grotto lit by lanterns that hung from a ceiling of overlapping boards propped up by a forest of stout beams. Shovels and picks lay in a heap in a corner; tall jars of black glass each as big as a hogshead barrel stood in a row along one wall; and something square and waist-high was shrouded in a red and gold Persian rug in the centre. 
Withers, his upper arm gripped by the enormous hand of the savage, shivered at my side while Brunel coolly walked around the perimeter, tapping the supports and advising Dr. Pretorius to have them wedged more tightly, before the whole enterprise collapsed upon him. 
Dr. Pretorius turned his greedy, exultant smile to me. "He doesn't know anything important, does he? Numbers and angles, cosines and arcs and logarithms, pounds per square inch—" he snapped his long white fingers, dismissing them. "We know, don't we, Mr. Carlyle, that such trivial calculations are of as much use as smoke in manipulating the true nature of the world. It is not matter which is important, but the forms that underlie matter. By mastering those forms, we can master the world, and the world beyond the world too." 
He strutted across the grotto, his mop of white curls brushing the ceiling, and ran a hand over the top of one of the squat jars, like a proud mother tousling the hair of a favoured child. "This is a new race of the children of men," he said, "formed by my own artifice and soon to be quickened by the life force I have discovered. A race able to live in both worlds at once, and mediate them directly. You and I have trained long in the matter of the living and the dead, Mr. Carlyle, but my creatures will be able to do all we can, and much more, as easily as breathing. And I will be their god." 
"Monsters," Withers said. His face was as pale as milk under his shock of red hair. 
"Quite so," Dr. Pretorius said. "A new world of gods and monsters!" 
He stepped up to the square form in the centre of the grotto and pulled the rug away, revealing a pediment constructed of heavy blocks of stained limestone and faced with a carving of a man riding a bull, with a familiar tangle of blackened bones draped across its dished top. 
"The altar of the temple of the sun-god, Mithras," he said. "Roman soldiers brought the cult to London, and sacrificed bulls to drive back the darkness of the forests around their fledgling city. They believed that the spilled blood of the bull killed by Mithras was the life force from which sprang every kind of plant and animal, and so the blood of their sacrifices has charged this altar with a special potency. At least one man was sacrificed too. His head was buried here, and his body was wrapped in a bull's hide and thrown into the River Fleet. At last, washed to and fro on the tides of many centuries, it came to rest above the path of Mr. Brunel's pitiful little tunnel. You feel its potency, don't you, Mr. Carlyle? Do not deny it—I can see in your face that you do." 
The carving on the front of the altar was very similar to the design of the buckle Brunel and I had found with Ulpius Silvanus's skeleton. I saw now that the man was not merely riding the bull: watched by two robed and hooded figures, one holding its torch high, the other low, he was pulling back the bull's head with his left hand while cutting its throat with a long narrow knife held in his right, all this within a ring in which dogs and scorpions and hares and fantastic chimeras chased each other's tails. 
As I stared at this carving, only half-hearing Dr. Pretorius's gloating speech, I saw a star kindle deep within the stone, and discovered that I could not look away. The star grew brighter and brighter until with a soundless explosion it burst open like a flower, shining beyond the limits of the stone. I cried out and clapped my hands over my eyes, but the light burned through everything. I could see, past the shadows of my own hand bones, the shadows of the bones within the flesh of the men around me; could see the misshapen homunculi stir in their black glass jars; could see at the heart of the light, like a pupa in its case, a ragged unformed figure jerking back and forth, as if trying to free itself. Then it stilled, and turned its terrible dark gaze toward me. 
Brunel told me later that I bellowed like a wounded bull and staggered backward and dropped to my knees, the heels of my hands pressed tight to my eyes. As everyone turned to look at me, he planted his back against the wall and kicked as hard as he could at one of the timbers which supported the roof. It gave with a rending sound and he kicked again and it dropped free, thumping on the stone floor as gravel and stones, and then a cascade of water burst out of the widening hole in the low ceiling. Wherever the water splashed on the stone floor it burst into steam, filling the little grotto with twisting snakes of white vapour, but most of the flood hung in the air as if pouring into an invisible mould: a glassy column that spun faster and faster, with the form of a man becoming dimly visible within it. 
I was jolted from my fugue by cold, filthy water washing over my knees, thighs and waist, and staggered to my feet as the flood continued to rise. For a moment, the glassy figure stared straight at me, and then the spinning column burst, drenching everyone and everything. Half the lanterns hung from the ceiling immediately went out; the rest swung crazily, sending shadows swarming around the flooded grotto. Dr. Pretorius was knocked down, his pale hands clawing above swirling water as his servants rushed to his aid, and I grabbed a pick and swung it at the dazzling block of the altar. 
I still do not know if the impulse was mine, or if it sprang from the knowledge which had been rammed into my brain. 
Black bones smashed; metal rang on stone. Drenched, half-blinded by light only I could see, I swung again and again. I was dimly aware that Withers was beside me, matching me stroke for stroke, and then one of the stones shattered and the burning flower burst like a soap bubble. The flood surged higher and we were all of us knocked down. Hardly aware of where I was, I breathed in a solid gush of water that seared all the way to the bottom of my lungs. Someone grabbed me and hauled me upright, and I saw, beyond a swarm of green and red afterimages, that Dr. Pretorius and his servants were battling an army of snakes made entirely of water. A glassy python surged around the trunk of the giant savage and bore him under; Dr. Pretorius was clinging with one arm to one of the black jars and swiping at darting ropes of water with the other. Then Brunel and Withers dragged me backward, through the half-flooded tunnel. 
The lake had risen too. Waves full of a milky light dashed over the bank, washing over our knees. The Lady Sophia swung back and forth at its mooring, banging against the stairway. At the far end of the lake, only the keystone of the arch showed above the restless water. 
We had climbed to the top of the tottering stairs when Brunel suddenly damned himself for a fool and swung over the rail. Withers tried to pull him back, but he shook off his assistant's grip, shouted that he would put an end to this and we must save ourselves, and swarmed down the frame of the stairs toward the tossing boat. I was still half-blinded and dizzy; Withers got his shoulder under me and helped me into the basement, where the two brothers were struggling furiously to free themselves of their bonds, and the servants Dr. Pretorius had left to guard them lay in insensible heaps on the stone floor. 
"They fell down like unstrung puppets just a moment ago," Thomas Dowling said, as Withers sawed at his ropes with a knife he had found on one of the unconscious servants. 
"I think they were intimately connected to Pretorius," I said. "Perhaps he is also unconscious." 
Withers said, "Only unconscious? I hope the monster is drowned." 
He had cut through the rope binding Thomas Dowling's arms, and had begun to free William, when Brunel appeared at the door, soaked through, wide-eyed, and breathless. "No time for that," he said. "She's set to blow!" 
We fled up a flight of stairs and burst through heavy curtains into a big room cluttered with cases and glass jars on stands. Faintly lit by lamplight that filtered through the gold-painted windows, a two-headed baby drowned in oily liquid inside a tall cylindrical jar opened both pairs of eyes and stared at me; at the same moment, the polished wood floor heaved violently and the curtains billowed out and a great gush of black smoke filled the room. Jars tottered and fell and smashed, the windows all fell in, and the floor heaved again and with a great groaning crack split jaggedly down the centre. 
Forty or fifty feet below our feet, the gaz engine of the Lady Sophia had exploded like a bomb. 
Everything in the museum slid toward the crack, gaining speed, smashing together, and dropping into the smoking abyss. Thomas Dowling hauled his brother up the tilted floor by the scruff of his shirt; I clung to Withers as he helped Brunel knock shards of glass from a windowframe. We piled through, sodden, smoke-begrimed, hatless and breathless. Roof tiles and broken glass smashed on the pavement all around. We picked ourselves up and ran, pursued by a great wave of smoke and plaster dust as the building dropped in on itself floor by floor, plummeting into the great cavity beneath. 

· · · · · 

June 1954 
No story is ever finished. 
I decided to write this account of my adventure with the brilliant young engineer after I read in the Times that an excavation under the direction of Professor W.F. Grimes of the Museum of London had uncovered the remains of a small Roman temple. It had been built in the early part of the third century, and sculptures and a silver incense box buried under the stone floor suggested it had been dedicated to the worship of the Persian god Mithras. 
I paid a visit that afternoon. The site was not on Farringdon Street, but within the old walls of the City, near the buried course of the Walbrook River. Raw new buildings of red brick or steel and concrete were springing up everywhere, but the considerable scars left by the war were still much in evidence. New office buildings and brief rows of surviving Victorian buildings stood amidst the rubble fields of bomb sites. Only a few months after the fire storms of the Blitz, these ruins had become fields of wild flowers as seeds buried for centuries woke in the ashes: lupins, poppies, pansies, violets, and, most notably, the yellow flowers of London Rocket. 
The site of the temple had been discovered while the foundations for an office block were being dug. The archaeologists worked in plain view, in an oblong terraced pit set at an oblique angle to the street. I confess to being gripped by considerable apprehension as I approached, but if there had ever been ghosts or other revenants at that place, they had long since departed. It was pleasant to lean on my cane in the warm sunlight and watch the crew of young men and women at work amongst a narrow maze of low stone walls set at different levels, uncovering the past inch by inch with trowels and paintbrushes, sifting soil through wire mesh pans, washing finds in rocking trays of water. 
I knew, as they did not, that this temple was not the first in London to be dedicated to Mithras. Dr. Pretorius had hunted out the original, and uncovered not only a source of power, but the site of an ancient tragedy. The temple founded by Ulpius Silvanus had stood just outside the boundary of the new city, beyond the western bank of the Fleet river. As the city grew and became more settled and civilized, and more and more soldiers retired from duty at the borders of the Empire to become merchants and traders, the Mithraic cult had become more concerned with fostering the business concerns of its members than with sacrifice, and a sizeable faction had argued that the temple should be resited inside the city, within the safety of the newly built city wall. Ulpius Silvanus had refused to listen to them, and they had murdered him on the altar of the temple he had built. 
I had learned all this in the instant I had confronted his ghost, and I had told the story to Brunel and the others as we warmed ourselves with brandy in the long shed at the site of the Thames Tunnel. 
"The ghost was bound to the skull buried beneath the altar, mingling with the puissance of the accumulated charge of the sacrifices, but it retained a connection to the rest of the bones, too. It was able to follow the ways of water like a spider at the centre of its web. That is why, I think, I felt no presence in the tunnel." 
Brunel favoured me with his sharp, inquisitive gaze. "Did any of Pretorius's boasts have substance, or was he a raving lunatic? I favour the latter, of course." 
"Amen," Withers said. 
"You did not see what was inside the altar," I said. 
"I saw you fall to your knees and cry out," Brunel said. "I saw the floodwater behaving strangely, as if vibrating to some harmonic, and all the rest was smash and flood and every man for himself." 
"You freed something," Withers said. He had a blanket draped over his shoulders, and although he was no longer shivering he was hunched into himself, clutching his glass of brandy in both hands. He said, "I felt it pass through me, like a wind." 
I said, "The ghost of Ulpius Silvanus has become something more than the ghost of a man, and something less than the ghost of a god." 
Brunel nodded, and for a moment we were all lost to each other in our own thoughts. Then he raised his glass and said, "Whatever we believe we saw—or did not see—we have defeated something evil. Let's be content with that." 
You know the rest of his story, of course. Work on the Thames Tunnel eventually resumed, and it was completed eleven years later. At Brunel's invitation I attended the opening ceremony and finally met his father; neither of us mentioned the skeleton we had retrieved from the river, or anything of our adventures. By then, Isambard Kingdom Brunel had become the most famous engineer of an age in which engineers were feted as heroes. He built more than a thousand miles of railway. He built bridges and viaducts and tunnels; although he did not live to see it completed, he designed the beautiful suspension bridge over Clifton Gorge. He built three great ships, and the strain of finishing the last of these, the Great Eastern, brought on his early death. 
It was at Napier Yard in the Isle of Dogs, in the shadow of his great, doomed ship, that I last saw him. It was a foul, rain-whipped night in late December, some twenty-five years after the affair of Dr. Pretorius and the lost temple. For the last four weeks, Brunel and his men had laboured unsuccessfully to ease the Great Eastern down steel tracks into the river, and now, to almost universal derision, the project was stalled. He was prematurely aged and very weary. He walked with the aid of a stick, and his face was haggard and deeply lined, and spots of hectic colour burned on his cheeks. His former energy showed only in his fierce gaze. 

· · · · · 

He had engaged me to discover if the series of accidents and frustrations which had dogged the launch had been caused by some malign ghost or spirit. I walked the canted, half-finished deck with him, in gusty rain that a freezing wind harried across the dark marshes and muddy fields, and at the end told him that I could find nothing. 
"It's good to know," he said, after we had repaired to the shelter of his office. He had a bad cough, and his voice rasped from an old injury to his throat. "The press is taunting me, I am plagued by the idiotic suggestions from half the cranks in England, my shipbuilder is so bitterly jealous of me, and so bad at managing his business, that he tries to avoid his commitments while at the same time demanding advance payments for work he has not done … So it is good to know that I must deal with a mere engineering problem. I have already ordered more hydraulic presses from the Tangye brothers. They are excellent men, and in the New Year I will have her afloat, I promise you. Unless, of course," he added, with a wry smile, "you could invoke that ghost from our old adventure, and raise such a tide that would float her, cradle and all, straight off the slipway." 
"That is beyond such little power I have, I fear," I said. 
Brunel insisted on paying my fee. "I would swear that you haven't aged a day since I last saw you," he said, as I drew on my Inverness cape. 
"It is one of the few perks of my trade." 
"You should—" he said, and was seized by a coughing fit, and had to take a drink of water before he could speak again. "You should teach me that trick. I still have so much to do." 
"It would take up all of your life, as it has mine. You would have no time for your great works." 
"Pretorius was right, wasn't he? There are two worlds, and you must choose which to inhabit." 
"He was wrong about most things," I said, "but he was right about that." 
I did not see Brunel again. The Great Eastern was launched in the New Year, but Brunel was still embroiled in disputes with his shipbuilder, who against his advice had been given the contract to outfit the ship. He suffered a massive stroke a few days before the Great Eastern's maiden voyage, and as he lay dying received news that two of the ship's boilers had exploded, destroying a funnel and the grand saloon, and killing six of the crew. His ship was so strongly built that she easily survived the disaster, but for Brunel it was a fatal blow, and he died the same night. 
As for Dr. Pretorius, he somehow survived the destruction of the lost temple, and a few years later quit the country for the United States, ahead of a scandal involving a patent electric elixir. At the time I write, he is living in some great style on the Baja Coast in Mexico, having made a fortune treating movie stars at his clinic. Although I admit that I have a faint professional curiosity about how he has lived to such a great age (my own springs naturally from my familiarity with the matter of the dead, I suspect that there is nothing natural about Dr. Pretorius's longevity), but I have no desire to see him again, or to ever attempt to invoke the mingled ghost of Mithras and Ulpius Silvanus. As for myself, I have continued in my trade. I know no other. 
Our stories have no proper endings, but are braided into a great unending tapestry, and each of us, living or dead, understands only a little of that grand design. 
I was still standing in the sunlight at the edge of the excavation, thinking of the young engineer, and Dr. Pretorius and the lost temple, when one of the archaeologists called to me. She was a slim, pretty young woman in dungarees and wellington boots, her hair tied up in a bright red scarf, her lively face further enlivened by a bold dash of lipstick, her hands on her hips as she looked up at me from the floor of the past. She had mistaken me for a visiting scholar, and wondered if I had business with Professor Grimes. He was away at a meeting, she said, and would not be back until tomorrow. 
"It is quite all right," I said. "I'm no more than an idle spectator. There is nothing to trouble me here." 
The End

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