Keyhole

	There's a story about a psychologist who was studying the intelligence of a chimpanzee. He led the chimp into a room full of toys, went out, closed the door and put his eye to the keyhole to see what the chimp was doing. He found himself gazing into a glittering interested brown eye only inches from his own. The chimp was looking through the keyhole to see what the psychologist was doing.

	When they brought Butch into the station in Tycho Crater he seemed to shrivel as the gravity coils in the air lock went on. He was impossible to begin with. He was all big eyes and skinny arms and legs, and he was very young and he didn't need air to breathe. Worden saw him as a limp bundle of bristly fur and terrified eyes as his captors handed him over.
	"Are you crazy?" demanded Worden angrily. "Bringing him in like this? Would you take a human baby into eight gravities? Get out of the way!"
	He rushed for the nursery that had been made ready for somebody like Butch. There was a rebuilt dwelling cave on one side. The other side was a human school room. And under the nursery the gravity coils had been turned off so that in that room things had only the weight that was proper to them on the Moon.
	The rest of the station had coils to bring everything up to normal weight for Earth. Otherwise the staff of the station would be seasick most of the time. Butch was in the Earth-gravity part of the station when he was delivered, and he couldn't lift a furry spindly paw.
	In the nursery, though, it was different. Worden put him on the floor. Worden was the uncomfortable one there -- his weight only twenty pounds instead of a normal hundred and sixty. He swayed and reeled as a man does on the Moon without gravity coils to steady him.
	But that was the normal thing to Butch. He uncurled himself and suddenly flashed across the nursery to the reconstructed dwelling-cave. It was a pretty good job, that cave. There were the five-foot chipped rocks shaped like dunce caps, found in all residences of Butch's race. There was the rocking stone on its base of other flattened rocks. But the spear stones were fastened down with wire in case Butch got ideas.
	Butch streaked it to these familiar objects. He swarmed up one of the dunce-cap stones and locked his arms and legs about its top, clinging close. Then he was still. Worden regarded him. Butch was motionless for minutes, seeming to take in as much as possible of his surroundings without moving even his eyes.
	Suddenly his head moved. He took in more of his environment. Then he stirred a third time and seemed to look at Worden with an extraordinary intensity --  whether of fear or pleading Worden could not tell.
	"Hmm," said Worden, "so that's what those stones are for! Perches or beds or roosts, eh? I'm your nurse, fella. We're playing a dirty trick on you but we can't help it."
	He knew Butch couldn't understand, but he talked to him as a man does talk to a dog or a baby. It isn't sensible, but it's necessary.
	"We're going to raise you up to be a traitor to your kinfolk," he said with some grimness. "I don't like it, but it has to be done. So I'm going to be very kind to you as part of the conspiracy. Real kindness would suggest that I kill you instead -- but I can't do that."
	Butch stared at him, unblinking and motionless. He looked something like an Earth monkey but not too much so. He was completely impossible but he looked pathetic.
	Worden said bitterly, "You're in your nursery, Butch. Make yourself at home!"
	He went out and closed the door behind him. Outside he glanced at the video screens that showed the interior of the nursery from four different angles. Butch remained still for a long time. Then he slipped down to the floor. This time he ignored the dwelling-cave of the nursery.
	He went interestedly to the human-culture part. He examined everything there with his oversized soft eyes. He touched everything with his incredibly handlike tiny paws. But his touches were tentative. Nothing was actually disturbed when he finished his examination.
	He went swiftly back to the dunce-cap rock, swarmed up it, locked his arms and legs about it again, blinked rapidly and seemed to go to sleep. He remained motionless with closed eyes until Worden grew tired of watching him and moved away.
	The whole alTair was preposterous and infuriating. The first men to land on the Moon knew that it was a dead world. The astronomers had been saying so for a hundred years, and the first and second expeditions to reach Luna from Earth found nothing to contradict the theory.
	But a man from the third expedition saw something moving among the upflung rocks of the Moon's landscape and he shot it and the existence of Butch's kind was discovered. It was inconceivable of course that there should be living creatures where there was neither air nor water. But Butch's folk did, live under exactly those conditions.
	The dead body of the first living creature killed on the Moon was carried back to Earth and biologists grew indignant. Even with a specimen to dissect and study they were inclined to insist that there simply wasn't any such creature. So the fourth and fifth and sixth lunar expeditions hunted Butch's relatives very earnestly for further specimens for the advancement of science.
	The sixth expedition lost two men whose spacesuits were punctured by what seemed to be weapons while they were hunting. The seventh expedition was wiped out to the last man. Butch's relatives evidently didn't like being shot as biological specimens.
	It wasn't until the tenth expedition of four ships established a base in Tycho Crater that men had any assurance of being able to land on the Moon and get away again. Even then the staff of the station felt as if it were under permanent siege.
	Worden made his report to Earth. A baby lunar creature had been captured by a tractor party and brought into Tycho Station. A nursery was ready and the infant was there now, alive. He seemed to be uninjured. He seemed not to mind an environment of breathable air for which he had no use. He was active and apparently curious and his intelligence was marked.
	There was so far no clue to what he ate -- if he ate at all -- though he had a mouth like the other collected specimens and the toothlike concretions which might serve as teeth. Worden would of course continue to report in detail. At the moment he was allowing Butch to accustom himself to his new surroundings.
	He settled down in the recreation room to scowl at his companion scientists and try to think, despite the program beamed on radar frequency from Earth. He definitely didn't like his job, but he knew that it had to be done. Butch had to be domesticated. He had to be persuaded that he was a human being, so human beings could find out how to exterminate his kind.
	It had been observed before, on Earth, that a kitten raised with a litter of puppies came to consider itself a dog and that even pet ducks came to prefer human society to that of their own species. Some talking birds of high intelligence appeared to be convinced that they were people and acted that way. If Butch reacted similarly he would become a traitor to his kind for the benefit of man. And it was necessary!
	Men had to have the Moon, and that was all there was to it. Gravity on the Moon was one eighth that of gravity on Earth. A rocket ship could make the Moon' voyage and carry a cargo, but no ship yet built could carry fuel for a trip to Mars or Venus if it started out from Earth.
	With a fueling stop on the Moon, though, the matter was simple. Eight drums of rocket fuel on the Moon weighed no more than on Earth. A ship itself weighed only one eighth as much on Luna. So a rocket that took off from Earth with ten drums of fuel could stop at a fuel base on the Moon and soar away again with two hundred, and sometimes more.
	With the Moon as'a fueling base men could conquer the solar system. Without the Moon mankind was earthbound. Men had to have the Moon!
	But Butch's relatives prevented it. By normal experience there could not be life on an airless desert with such monstrous extremes of heat and cold as the Moon's surface experienced. But there was life there. Butch's kinfolk did not breathe oxygen. Apparently they ate it in some mineral combination and it interacted with other minerals in their bodies to yield heat and energy.
	Men thought squids peculiar because their blood stream used copper in place of iron, but Butch and his kindred seemed to have complex carbon compounds in place of both. They were intelligent in some fashion, it was clear. They used tools, they chipped stone, and they had long, needlelike stone crystals which they threw as weapons.
	No metals, of course, for lack of fire to smelt them. There couldn't be fire without air. But Worden reflectéd that in ancient days some experimenters had melted metals and set wood ablaze with mirrors concentrating the heat of the sun. With the naked sunlight of the Moon's surface, not tempered by air and clouds, Butch's folk could have metals if they only contrived mirrors and curved them properly like the mirrors of telescopes on Earth.
	Worden had an odd sensation just then. He looked around sharply as if somebody had made a sudden movement. But the video screen merely displayed a comediain back on Earth, wearing a funny hat. Everybody looked at the screen.
	As Worden watched, the comedian was smothered in a mass of soapsuds and the studio audience two hundred and thirty thousand miles away squealed and applauded the exquisite humor of the scene. In the Moon station in Tycho Crater somehow it was less than comical.
	Worden got up and shook himself. He went to look again at the screens that showed the interior of the nursery. Butch was motionless on the absurd cone-shaped stone. His eyes were closed. He was simply a furry, pathetic little bundle, stolen from the airless wastes outside to be bred into a traitor to his own race.
	Worden went to his cabin and turned in. Before he slept, though, he reflected that there was still some hope for Butch. Nobody understood his metabolism. Nobody could guess at what he ate. Butch might starve to death. If he did he would be lucky. But it was Worden's job to prevent it. Butch's relatives were at war with men. The tractors that crawled away from the station -- they went amazingly fast on the Moon -- were watched by big-eyed furry creatures from rock crevices and from behind the boulders that dotted the lunar landscape. Needle-sharp throwing stones flicked through emptiness. They splintered on the tractor bodies and on the tractor ports, but sometimes they jammed or broke a tread and then the tractor had to stop. Somebody had to go out and clear things or make repairs. And then a storm of throwing stones poured upon him.
	A needle-pointed stone, traveling a hundred feet a second, hit just as hard on Luna as it did on Earth --  and it traveled farther. Spacesuits were punctured. Men died. Now tractor treads were being armored and special repair-suits were under construction, made of hardened steel plates. Men who reached the Moon in rocket ships were having to wear armor like medieval knights and men-at-arms! There was a war on. A traitor was needed. And Butch was elected to be that traitor.

	When Worden went into the nursery again -- the days and nights on the Moon are two weeks-long apiece, so men ignored such matters inside the station -- Butch leaped for the dunce-cap stone and clung to its top. He had been fumbling around the rocking stone. It still swayed back and forth on its plate. Now he seemed to try to squeeze himself to unity with the stone spire, his eyes staring enigmatically at Worden.
	"I don't know whether we'll get anywhere or not," said Worden conversationally. "Maybe you'll put up a fight if I touch you. But we'll see."
	He reached out his hand. The small furry body --  neither hot nor cold but the temperature of the air in the station -- resisted desperately. But Butch was very young. Worden peeled him loose and carried him across the room to the human schoolroom equipment. Butch curled up, staring fearfully.
	"I'm playing dirty," said Worden, "by being nice to you, Butch. Here's a toy."
	Butch stirred in his grasp. His eyes blinked rapidly. Worden put him down and wound up a tiny mechanical toy. It moved. Butch watched intently. When it stopped he looked back at Worden. Worden wound it up again. Again Butch watched. When it ran down a second time the tiny handlike paw reached out.
	With an odd tentativeness, Butch tried to turn the winding key. He was not strong enough. After an instant he went loping across to the dwelling-cave. The winding key was a metal ring. Butch fitted that over a throw-stone point, and twisted the toy about. He wound it up. He put the toy on the floor and watched it work. Worden's jaw dropped.
	"Brains!" he said' wryly. "Too bad, Butch! You know the principle of the lever. At a guess you've an eight-year-old human brain! I'm sorry for you, fella!"
	At the regular communication hour he made his report to Earth. Butch was teachable. He only had to see a thing done once -- or at most twice -- to be able to repeat the motions involved.
	"And," said Worden, carefully detached, "he isn't afraid of me now. He understands that I intend to be friendly. While I was carrying him I talked to him. He felt the vibration of my chest from my voice. "Just before I left him I picked him up and talked to him again. He looked at my mouth as it moved and put his paw on my chest to feel the vibrations. I put his paw at my throat. The vibrations are clearer there. He seemed fascinated. I don't know how you'd rate his intelligence but it's above that of a human baby."
	Then he said with even greater detachment, "I am disturbed. If you must know, I don't like the idea of exterminating his kind. They have tools, they have intelligence. I think we should try to communicate with them in some way -- try to make friends -- stop killing them for dissectiop." -
	The communicator was silent for the second and a half it took his voice to travel to Earth and the second and a half it took to come back. Then the recording clerk's voice said bristly, "Very good, Mr. Worden! Your voice was very clear!"
	Worden shrugged his shoulders. The lunar station in Tycho was a highly official enterprise. The staff on the Moon had to be competent -- and besides, political appointees did not want to risk their precious lives -- but the Earth end of the business of the Space Exploration Bureau was run by the sort of people who do get on official payrolls; Worden felt sorry for Butch -- and for Butch's relatives.

	In a later lesson session Worden took an empty coffee tin into the nursery. He showed Butch that its bottom vibrated when he spoke into it, just as his throat did. Butch experimented busily. He discovered for himself that it had to be pointed at Worden to catch the vibrations.
	Worden was. unhappy. He would have preferred Butch to be a little less rational. But for the next lesson he presented Butch with a really thin metal diaphragm stretched across a hoop. Butch caught the idea at once.
	When Worden made his next report to Earth he felt angry.
	"Butch has no experience of sound as we have, of course," he said curtly. "There's no air on the Moon. But sound travels through rocks. He's sensitive to vibrations in solid objects just as a deaf person can feel the vibrations of a dance floor if the music is loud enough.
	"Maybe Butch's kind has a language or a code of sounds sent through the rock underfoot. They do communicate somehow! And if they've brains and a means of communication they aren't animals and shouldn't be exterminated for our convenience!"
	He stopped. The chief biologist of the Space Exploration Bureau was at the other end of the communication beam then. After the necessary pause for distance his voice came blandly.
	"Splendid, Worden! Splendid reasoning! But we have to take the longer view. Exploration of Mars and Venus is a very popular idea with the public. If we are to have funds -- and the appropriations come up for a vote shortly -- we have to make progress toward the nearer planets. The public demands it. Unless we can begin work on a refueling base on the Moon, public interest will cease!"
	Worden said urgently, "Suppose I send some pictures of Butch? He's very human, sir! He's extraordinarily appealing! He has personality! A reel or two of Butch at his lessons ought to be popular!"
	Again that irritating wait while his voice traveled a quarter million miles at the speed of light and the wait for the reply.
	"The -- ah -- lunar creatures, Worden," said the chief biologist regretfully, "have killed a number of men who have been publicized as martyrs to science. We cannot give favorable publicity to creatures that have killed men!" Then he added blandly, "But you are progressing splendidly, Worden -- splendidly! Carry on!"
	His image faded from the video screen. Worden said naughty words as he turned away-. He'd come to like Butch. Butch trusted him. Butch now slid down from that crazy perch of his and came rushing to his arms every time he entered the nursery.
	Butch was ridiculously small -- no more than eighteen inches high. He was preposterously light and fragile in his nursery, where only Moon gravity obtained. And Butch was such an earnest little creature, so soberly absorbed in everything that Worden showed him!
	He was still fascinated by the phenomena of sound. Humming or singing -- even Worden's humming and singing -- entranced him. When Worden's lips moved now Butch struck an attitude and held up the hoop diaphragm with a tiny finger pressed to it to catch the vibrations Worden's voice made.
	Now too when he grasped an idea Worden tried to convey, he tended to swagger. He became more human in his actions with every session of human contact. Once, indeed, Worden looked at the video screens which spied on Butch and saw him -- all alone --  solemnly going through every gesture and every movement Worden had made. He was pretending to give a lesson to an imaginary still tinier companion. He was pretending to be Worden, apparently for his own satisfaction!
	Worden felt a lump in his throat. He was enormously fond of the little mite. It was painful that he had just left Butch to help in the construction of a vibrator microphone device which would transfer his voice to rock vibrations and simultaneously pick up any other vibrations that might be made in return.
	If the members of Butch's race did communicate by tapping on rocks or the like, men could eavesdrop on them -- could locate them, could detect ambushes in preparation, and apply mankind's deadly military countermeasures.
	Worden hoped the gadget wouldn't work. But it did. When he put it on the floor of the nursery and spoke into the microphone, Butch did feel the vibrations underfoot. He recognized their identity with the vibrations he'd learned to detect in air.
	He made a skipping exultant hop and jump. It was plainly the uttermost expression of satisfaction. And then his tiny foot pattered and scratched furiously on the floor. It made a peculiar scratchy tapping. noise which the microphone picked up. Butch watched Worden's face, making the sounds which were like highly elaborated ***footf ails***.
	"No dice, Butch," said Worden unhappily. "I can't understand it. But it looks as if you've started your treason already. This'll help wipe out some of your folks."

	He reported it reluctantly to the head of the station.
	Microphones were immediately set into the rocky crater floor outside the station and others were made ready for exploring parties to use for the detection of Moon creatures near them. Oddly enough, the microphones by the station yielded results right away.
	It was near sunset. Butch had been captured near the middle of the three-hundred-and-thirty-four-hour lunar day. In all the hours between -- a week by Earth time -- he had had no nourishment of any sort. Worden had conscientiously offered him every edible and inedible substance in the station. Then at least one sample of every mineral in the station collection. Butch regarded them all with interest but without appetite. Worden -- liking Butch -- expected him to die of starvation and thought it a good idea. Better than encompassing the death of all his race, anyhow. And it did seem to him that Butch was beginning to show a certain sluggishness, a certain lack of bounce and energy. He thought it was weakness from hunger.
	Sunset progressed. Yard by yard, fathom by fathom, half-mile by half-mile, the shadows of the miles-high western walls of Tycho crept across the crater floor. There came a time when only the central hump had sunlight. Then the shadow began to creep up the eastern walls. Presently the last thin jagged line of light would vanish and the colossal cup of the crater would be filled to overflowing with the night.
	Worden watched the incandescent sunlight growing even narrower on the cliffs. He would see no other sunlight for two weeks' Earth time. Then abruptly an alarm bell rang. It clanged stridently, furiously. Doors hissed shut, dividing the station into airtight sections.
	Loudspeakers snapped, "Noises in the rock outside! Sounds like Moon creatures talking nearby! They may plan an attack! Everybody into spacesuits and get guts ready!"
	At just that instant the last thin sliver of sunshine disappeared. Worden thought instantly of Butch. There was no spacesuit to fit him. Then he grimaced a little. Butch didn't need a spacesuit.
	Worden got into the clumsy outfit. The lights dimmed. The harsh airless space outside the station was suddenly bathed in light. The multimillion-lumen beam, made to guide rocket ships to a landing even at night, was turned on to expose any creatures with designs on its owners. It was startling to see how little space was really lighted by the beam and how much of stark blackness spread on beyond.
	The loudspeaker snapped again. "Two Moon creatures! Running away! They're zigzagging! Anybody who wants to take a shot -- " The voice paused. It didn't matter. Nobody is a crack shot in a spacesuit. "They left something behind!" said the voice in the loudspeaker. It was sharp and uneasy. -
	"I'll take a look at that," said Worden. His own voice startled him but he was depressed. "I've got a hunch what it is."
	Minutes later he went out through the air lock. He moved lightly despite the cumbrous suit he wore. There were two other staff members with him. All three were armed and the searchlight beam stabbed here and there erratically to expose any relative of Butch who might try to approach them in the darkness.
	With the light at his back Worden could see that trillions of stars looked down upon Luna. The zenith was filled with infinitesimal specks of light of every conceivable color. The familiar constellations burned ten times as brightly as on Earth. And Earth itself hung nearly overhead. It was three-quarters full -- a monstrous bluish giant in the sky, four times the Moon's diameter, its ice caps and continents mistily to be seen. -
	Worden went forebodingly to the object left behind by Butch's kin. He wasn't much surprised when he saw what it was. It was a rocking stone on its plate with a fine impalpable dust on the plate, as if something had been crushed under the egg-shaped upper stone acting as a mill.
	Worden said sourly into his helmet microphone, "It's a present for Butch. His kinfolk know he was captured alive. They suspect he's hungry: They've left some grub for him of the kind he wants or needs most."
	That was plainly what it was. It did not make Worden feel proud. A baby -- Butch -- had been kidnapped by the enemies of its race. That baby was a prisoner and its captors would have nothing with which to feed it. So someone, greatly daring -- Worden wondered somberly if it was Butch's father and mother -- had risked their lives to leave food for him with a rocking stone to tag it for recognition as food.
	"It's a dirty shame," said Worden bitterly. "All right! Let's carry it back. Careful not to spill the powdered stuff!"
	His lack of pride was emphasized when Butch fell upon the unidentified powder with marked enthusiasm. Tiny pinch by tiny pinch Butch consumed it with an air of vast satisfaction. Worden felt ashamed.
	"You're getting treated pretty rough, Butch," said Worden. "What I've already learned from you will cost a good many hundred of your folks' lives. And they're taking chances to feed you! I'm making you a traitor and myself a scoundrel." -

	Butch thoughtfully held up the hoop diaphragm to catch the voice vibrations in the air. He was small and furry and absorbed. He decided that he could pick up sounds better from the rock underfoot. He pressed the communicator microphone on Worden. He waited.
	"No!" said Worden roughly. "Your people are too human. Don't let me find out any more, Butch. Be smart and play dumb!"
	But Butch didn't, It wasn't very long before Worden was teaching him to read. Oddly, though, the rock microphones that had given the alarm at the station didn't help the tractor parties at all. Butch's kinfolk seemed to vanish from the neighborhood of the station altogether. Of course if that kept up, the construction of a fuel base could be begun and the actual extermination of the species carried out later. But the reports on Butch were suggesting other possibilities.
	"If your folks stay vanished," Worden told Butch, "it'll be all right for a while -- and only for a while. I'm being urged to try to get you used to Earth gravity. If I succeed, they'll want you on Earth in a zoo. And if that works -- why, they'll be sending other expeditions to get more of your kinfolk to put in other zoos."
	Butch watched Worden, motionless. "And also" -- Worden's tone was very grim -- "there's some miniature mining machinery coming up by the next rocket. I'm supposed to see if you can learn to run it."
	Butch made scratching sounds on the floor. It was unintelligible of course, but it was an expression of interest at least. Butch seemed to enjoy the vibrations of Worden's voice, just as a dog likes to have his master talk to him. Worden grunted.
	"We humans class you as an animal, Butch. We tell ourselves that all the animal world should be subject to us. Animals should work for us. If you act too smart well hunt down all your relatives and set them to work digging minerals for us. You'll be with them. But I don't want you to work your heart out in a mine, Butch! It's wrong!"
	Butch remained quite still. Worden thought sickishly of small furry creatures like Butch driven to labor in airless mines in the Moon's frigid depths. With guards in spacesuits watching lest any try to escape to the freedom they'd known before the coming of men. With guns mounted against revolt. With punishments- for rebellion or weariness.
	It wouldn't be unprecedented. The Indians in Cuba when the Spanish càme . . . Negro slavery in both Americas . . . concentration camps . . .
	Butch moved. He put a small furry paw on Worden's knee. Worden scowled at him.
	"Bad business," he said harshly. "I'd rather not get fond of you. You're a likable little cuss but your race is doomed. The trouble is that you didn't bother to develop a civilization. And if you had, I suspect we'd have smashed it. We humans aren't what you'd call admirable." -
	Butch went over to the blackboard. He took a piece of pastel chalk -- ordinary chalk was too hard for his Moon-gravity muscles -to use -- and soberly began to make marks on the slate. The marks formed letters. The letters made words. The words made sense.
	YOU, wrote Butáh quite incredibly in neat pica lettering, GOOD FRIEND.
	He turned his head to stare at Worden. Worden went white. "I haven't taught you those words, Butch!" he said very quietly. "What's up?"
	He'd forgotten that his words, to Butch, were merely vibrations in the air or in the floor. He'd forgotten they had no meaning. But Butch seemed to have forgotten it too. He marked soberly:	-
	MY FRIEND GET SPACESUIT. He looked at Worden and marked once more. TAKE ME OUT. I COME BACK WITH YOU.
	He looked at Worden with large incongruously soft and appealing eyes. And Worden's brain seemed to spin inside his skull. After a long time Butch printed again --  YES.
	Then Worden sat very still indeed. There was only Moon gravity in the nursery and he weighed only one eighth as much as on Earth. But he felt very weak. Then he felt grim.
	"Not much else to do, I suppose," he said slowly. "But I'll have to carry you through Earth gravity to the air lock."
	He got to his feet. Butch made a little leap up into his arms. He curled up there, staring at Worden's face. Just before Worden stepped through the door Butch reached up a skinny paw and caressed Worden's cheek tentatively.
	"Here we go!" said Worden. "The idea was for you to be a traitor. I wonder -- "
	But with Butch a furry ball, suffering in the multiplied weight Earth-gravity imposed upon him, Worden made his way to the air lock. He donned a spacesuit. He went out.
	It was near sunrise then. A long time had passed and Earth was now in its last quarter and the very highest peak of all that made up the crater wall glowed incandescent in the sunshine. But the stars were still quite visible and very bright. Worden walked away from the station, guided by the Earth-shine on the ground under foot.
	Three hours later he came back. Butch skipped and hopped beside his spacesuited figure. Behind them came two other figures. They were smaller than Worden but much larger than Butch. They were skinny and furry and they carried a burden. A mile from the station he switched on his suit radio. He called. A startled voice answered in his earphones.
	"It's Worden," he said dryly. "I've been out for a walk with Butch. We visited his family and I've a couple of his cousins with me. They want to pay a visit and present some gifts. Will you let us in without shooting?"
	There were exclamations. There was confusion. But Worden went on steadily toward the station while another high peak glowed in sunrise light and a third seemed to burst into incandescence. Dawn was definitely on the way.
	The aft-lock door opened. The party from the airless Moon went in. When the air lock filled, though, and the gravity coils went on, BUtch and his relatives became helpless. They had to be carried to the nursery. There they uncurled themselves and blinked enigmatically at the men who crowded into the room where gravity was normal for the Moon and at the other men who stared in the door.
	"I've got a sort of message," said Worden. "Butch and his relatives want to make a deal with us. You'll notice that they've put themselves at our mercy. We can kill all three of them. But they want to make a deal."
	The head of the station said uncomfortably, "You've managed two-way communication, Worden."
	"1 haven't," Worden told him. "They have. They've proved to me that they've brains equal to ours. They've been treated as animals and shot as specimens They've fought back -- naturally! But they want to make friends. They say that we can never use the Moon except in spacesuits and in stations like this, and they could never take Earth's gravity. So there's no need for us to be enemies. We can help each other."
	The head of the station said dryly, "Plausible enough, but we have to act under orders, Worden. Did you explain that?"
	"They know," said Worden. "So they've got set to defend themselves if necessary. They've set up smelters to handle metals. They get the heat by sun mirrors, concentrating sunlight. They've even begun to work with gases held in containers. They're not far along with electronics yet, but they've got the theoretic knowledge and they don't need vacuum tubes. They live in a vacuum. They can defend themselves from now on."
	The head said mildly, "I've watched Butch, you know, Worden. And you don't look crazy. But if this sort of thing is sprung on the armed forces on Earth there'll be trouble. They've been arguing for armed rocket ships. If your friends start a real war for defense -- if they can -- maybe rocket warships will be the answer."	 -- 
	Worden nodded.
	"Right. But our rockets aren't so good that they can fight this far from a fuel store, and there couldn't be --  one on the Moon with all of Butch's kinfolk civilized --  -- as they nearly are now and as they certainly will be within the next few weeks. Smart people, these cousins'and such of Butch!"		-
	"I'm afraid they'll have to prove it," said the head "Where'd they get this sudden surge in culture?"
	"From us," said Worden. "Smelting from me, I think. Metallurgy and mechanical engineering from the tractor mechanics. Geology -- call it lunology here -- mostly from you."
	"How's that?" demanded the head.
	"Think of something you'd like Butch to do," said Worden grimly, "and then watch him." 
	The head stared and then looked at Butch. Butch --  small and furry and swaggering -- stood up and bowed profoundly from the waist. One paw was placed where his heart could be. The other made a grandiose sweeping gesture. He straightened up and strutted, then climbed swiftly into Worden's lap and put a skinny furry arm about his neck.
	"That bow," said the head, very pale, "is what I had in mind. You mean -- "
	"Just so," said Worden. "Butch's ancestors had no air to make noises in for speech. So they developed telepathy. In time, to be sure, they worked out something like music -- sounds carried through rock. But like our music it doesn't carry meaning. They communicate directly from mind to mind. Only we can't pick up communications from them and they can from us."
	"They read our minds!" said the head. He licked his lips. "And when we first shot them for specimens they were. trying to communicate. Now they fight."
	"Naturally," said Worden. "Wouldn't we? They've been picking our brains. They can put up a terrific battle now. They could wipe out this station without trouble. They let us stay so they could learn from us. Now they want to trade."
	"We have to report to Earth," said the head slowly, "but -- " -
	"They brought along some samples," said Worden. "They'll swap diamonds, weight for weight, for records. They like our music. They'll trade emeralds for textbooks -- they can read now! And they'll set up an atomic pile and swap plutonium for other things they'll think of later. Trading on that basis should be cheaper than war!"
	"Yes," said the head. "It should. That's the sort of argument men will listen to. But how --  -- "
	"Butch," said Worden ironically. "Just Butch! We didn't capture him -- they planted him on us! He stayed in the station and picked our brains and relayed the stuff to his relatives. We wanted to learn about them, remember? It's like the story of the psychologist. . .

	There's a story about a psychologist who was studying the intelligence of a chimpanzee. He led the chimp into a room full of toys, went out, closed the door and put his eye to the keyhole to see what the chimp was doing. He found himself gazing into a glittering interested brown-eye only inches from his own. The chimp was looking through the keyhole to see what the psychologist was doing.