MURRAY LEINSTER PROPAGANDIST You REMEMBER the Space Assassins, of course. They were that race of which no human being ever saw a living member, and escaped to tell about it afterward. You also remember the deadly, far-flung search that was made for their base, their home. They'd been sniping our ships for a long time. But then a squadron of their space fleet raided the Earth colony on Capella Three and without warning or provocation or alternative slaughtered every one of the colony's half million human population. Then the hunt for them began. This is the story of one of the incidents of that hunt —and also it's the story of a dog named Buck. Buck trailed his master sedately into the control room of the light cruiser Kennessee. He waited patiently until the skipper looked up from the electron telescope. Then Buck's master—Holden—sat down with the sheaf of wave records he'd brought from the communications room. Buck blinked wisely at the skipper and lay down on the floor with an audible, loose-jointed thump. He put his nose between his paws and sighed heavily. But the sigh was not of un-happiness. Buck was a simple dog. He was friendly with everybody on the Kennessee, from the skipper himself to the lowliest mess boy, but his master and private deity was Junior Lieutenant Holden. Whithersoever Holden went, there Buck went also—regulations permitting—and waited until Holden wanted to go somewhere else. Now he ky on the foamite flooring. He heard his master's voice, and the skipper's in reply. They were concerned and uneasy. Buck dozed. Little, half-formed dreams ran through his slumber. Memory dreams, mostly, of himself racing gloriously through tall grass on the green fields of Earth, with Holden always somewhere near. The voices of the two men formed a half-heard background to his dozing. The men were troubled. The Kennessee rode a comet's orbit through the solar system of Masa Gamma, her drive off and giving no sign of life. She was impersonating a barren visitor from the void, spying out the ground for what would be—if she was successful—the monstrous destruction of an entire race by planet-smasher guided missiles and the merciless weapons of an Earth fleet. The men did not like it. They'd hoped that some other ship would be the one to meet with success in its search. But they had their orders. Some weeks back the ship had dropped from overdrive to less-than-light speed far beyond the outermost of the Masa Gamma planets. She'd decelerated to an appropriate speed and course for a wanderer, and she'd begun her ride along a comet's path through the eleven-planet system. And almost immediately her receptors had picked up evidence of civilization here. Space radio signals. They were unintelligible, of course, but they told that here was a civilization comparable to human culture on a technical basis. And that was what the Keimessee, with every other light ship of Earth's space navy, was hunting for. There was a race which, without known contact with Earthmen, was the deadly enemy of humanity. For years past, exploring ships from Earth had dropped out of sight with ominous frequency. There had been suspicions, but no proof of an inimical race which destroyed humans wherever it came upon them. But six months ago the Earth colony on Capella Three had been wiped out, terribly, by raiders of whom nothing was known except that they were not human. So somewhere there was a race which held Earth to be its enemy. It had to be found. If it could not be negotiated with, it must be destroyed before it grew strong enough to wipe out all of humankind. And the men on the Kennessee knew that they might have found it on the planets of Masa Gamma. This system had never been explored before, and this civilization which had space radio might be the one— Buck, the dog, dozed lightly on the control-room floor. Little fragments of dreams ran through his half-slumbering consciousness: the smells in the engine room; an irrelevant fragment of chasing a cat; a moment or two in which he sniffed elaborately at a tree ... A slightly louder comment made him open his eyes. "They've interplanetary travel, sir, at least"—that was Holden. "We've picked up space-radio messages from definitely between planets. It looks like this is the race we were sent to find." The skipper nodded. "It could be. But if they're to be smashed on our report, we need to make sure. That's orders, too. Can they smash the Kennessee? That's the test for the enemy. If this race can't kill us, they're not the enemy we're looking for. If they can, they are. We've got to find out." "But interplanetary travel is good evidence—" "It's not interstellar travel," said the skipper. "We'll send a torp back immediately with all the data to date. But you've picked up no whango waves, Holden. We've no proof that these folk can travel between the stars. The enemy can." "They might be concealing the fact," said Holden. "They'd have picked up our whango wave on arrival. They might be laying for us, waiting for us to walk into their parlor where they can smash us without a chance to fight back or report. That would be typical." He stood up and Buck got immediately to his four paws and wagged his tail. His master, Holden, was going to go somewhere. So Buck was going with him. He waited contently. To Buck, happiness was going where Holden went, being wherever Holden was, simply soaking in the sensation of being with Holden. It was a very simple pleasure, but it was all he asked of fate or chance. When Holden petted him or played roughly with him, Buck was filled with ecstatic happiness, but now he waited contentedly enough simply to follow Holden. "What you say is true enough," agreed the skipper. "They could be laying for us. We'll see. A message torp will make sure that if we don't get back our fleet will know where to come and who to smash. Then we'll make a landing in a lifeboat. Our enemy couldn't resist smashing that! And if it gets away, we'll know something about their weapons, anyhow." "I volunteer, sir, for the lifeboat," said Holden quickly. "We'll see," said the skipper. "You get your data ready for the torp. You're sure this record is a scanning beam? Like the old-fashioned radar? And it's being kept on us from this fourth planet?" "Quite sure, sir," said Holden. "We can't know how detailed the information may be that it takes back. Of course, it would be logical enough to scan a supposed comet—" "Let's hope," said the skipper, twinkling, "that the echo from our hull says, 'Nobody out here but us comets, boss.' Get your stuff ready for half an hour from now, Holden." Holden saluted and went out of the control room. Buck went sedately after him, a large brown dog who did not bother his head over such trivia as interstellar travel or nonhuman races that massacred half a million humans with an insensate ferocity. Buck was a very contented dog. He was with his master. The Planetary Council of Masa Four was in session. It was not a happy gathering. Scanning beams had reported that a supposed new comet, driving in on a perfectly convincing orbit, was actually an artifact— a spaceship. It used no drive and seemed empty of life. But it had come in through the gravitation field of the outermost planets—and it showed no sign of rotation. Which was impossible unless gyroscopes or some similar device were running within it. "We have had one visitor from space, before," said the Moderator of the Planetary Council. He looked very weary. "Our histories tell us of the consequences. If this is another ship of the same race, we must destroy it. Since it is attempting secrecy, such action is justified, I think. But that secrecy suggests suspicion of us—a suspicion that we may have destroyed the last visitor. If we destroy this ship also, we may be sure that suspicion will become certainty and a third visit will be made in overwhelming force. That means that we will have to convert our whole civilization for war. We will have somehow to develop an interstellar drive, and we will have to spend the rest of the time in battle for our very survival. We will have to change from a peaceful race to one with a psychology adapted only to war." The Spokesman for the First Continent said hopefully: "Is it certain that this is a ship of the same race as the first? It is not of the same form. Is it certain that this race is of a not-possibly-friendly type, like the first?" "It is not certain," said the Moderator tiredly. "The psychological factors implied by its outer design suggest a different race. But can we risk an attempt at peaceful contact? The crew of one ship would be at our mercy. Might they not pretend friendship in order to escape with information leading to our destruction? Could we trust the friendship of any race at all which sent a single ship to spy?" There was silence. Two centuries before, another ship had entered the Masan system. Half a planet devastated, and millions upon millions of lives, had been the cost of the destruction of that one ship. But its destruction had been necessary. Its crew made no response to peaceful overtures. Wherever they landed they destroyed, ferociously, everything savoring of a rival civilization. Especially the inhabitants. They could not be treated with—only killed. "If," said the Spokesman for the Third Continent wistfully, "we could capture a single member of this spaceship's crew, we could make sure that friendship was hopeless. It is a pity we cannot make sure before—" "It is a great pity," said the Moderator bleakly. "To convert not only our civilization but our people to endless war, for all time, is the greatest of pities. But I do not think there is anything else to do. Will you vote upon preparations for the destruction of this ship?" The vote was reluctant but unanimous. For war. The Kermessee sent off the torp from the aft communications room. It was not an impressive device, the torp, merely a cigar-shaped object some six feet long. After leaving the Kemessee it would drive away at thirty-five gravities' acceleration for fifteen minutes and then go into overdrive—when it would cease to exist, as far as normal space was concerned. Its disappearance would be marked by the emission of a monstrous surge of energy—a "whango wave"—which could be detected at hundreds of millions of miles. Near home base it would come out of overdrive with the emission of another, similar, wave. The second wave was useful. From Masa Gamma to the Kermessee's home base was some eighty light-years. A space-radio message transmitted by tight beam would reach home base only in time to be of interest to the crew's greatgrandchildren. But the torp would arrive within days, its reappearance wave would be picked up by a far-flung net of communications ships, and they would receive and forward the torp's automatically transmitted messages, and later pick it up for the recovery of written data and physical specimens. Buck was not allowed to be present at the launching. He was a large dog, and the aft communications room was in the tapering, slender tail of the Kermessee. It would be crowded. Holden ordered him out. And Buck was far too well assured, both of Holden's affection for him and of his own worth, to be sensitive about such a matter. He knew there were times when he couldn't be underfoot. But he also knew that he was welcome anywhere else on the ship. He went trotting sedately in search of inferior, but still human, com- pany until his master could allow him around again. He found crew members stocking a lifeboat for its special mission. He went companionably into the lifeboat with the working party. He wriggled into the control cubicle with the man sent to remove its records —and observed. Presently other men arrived, the work party left, and there were sundry heaving movements of the lifeboat. Buck blinked from where he lay more or less curled up on the floor. Stars shone in the lifeboat portholes. There was a glaring bright light. Unshielded sunshine from Masa Gamma came in a forward port and made a patch of incandescence on the back wall. Junior Lieutenant Maynard walked into the control cubicle and flipped the phone switch. "Lifeboat in launching position, blister removed, ready to take off," he said briskly. "All right," said Holden's voice from the speaker. It sounded gloomy. "Take off when the whango wave hits. It may jam their scanner and get you out of the beam unobserved. Luck." Buck knew loud-speakers. But also he knew his master's voice. He wagged his tail. It thumped. Maynard jerked his head around and yelled: "Buck! Here's Buck! Behind me!" An instant's silence. Then Holden's voice, more gloomy still. "No time to get him back on board. He'll have to go along. Sorry, Maynard." "No harm," said Maynard cheerfully. "Maybe he'll mascot us. How much time?" "Twenty seconds," said Holden's voice. "You have all the luck! I was high man for this job until you drew that ace!" Maynard chuckled. The Kennessee rode into a very probably hostile solar system. If it was the home of the race that had been sniping off Earth ships and had massacred the colonists of Capella Three, there was not much chance that the cruiser would ever get away again. But its junior officers had played a hand of stud poker for the privilege of making a dare-landing on the system's largest planet. The speaker suddenly emitted a sound so savage and so loud that the diaphragm jangled musically only once, and then made strangled, rasping noises. That was the whango wave of the message torp. It was a blast of untuned and untunable radiation which would jam every receiver in range while it lasted. There was a crushing feeling of weight. Buck slid back against the back rest of the seat on which he now lay. He was pressed hard against the upholstery. He wriggled and panted. His eyes grew plaintive. Buck did not like acceleration. In fact, he did not like lifeboat travel. But he had his fill of it in the next eighteen hours, anyhow. A message arrived at the hastily improvised Department of War on Masa Four. The Department of War was being feverishly organized to coordinate every erg of energy in the entire solar system into synchrophased power beams which at a given moment would stab out from four planets at once—all of them on the same side of the local sun—and converge terribly upon the pseudo comet. There would be no material weapon for the ship's detectors to note in time for any maneuver of escape. This weapon would strike at the speed of light. An object in the focus of the combined beams would experience the interior temperature of a sun. It was unthinkable that any possible relay could operate before it was volatilized. The weapon was irresistible—as against a single ship. But the computation of phase relationships for the moving planetary projectors, so that the separate beams would reinforce instead of partially canceling one another, was a matter of terrifying complexity. This weapon could destroy one ship of known course and speed, or one ship on the ground, if enough time could be had for calculations. But it would be useless against a fleet. Days or weeks were required for the adjustment of the multitude of beams for a hit on a predetermined spot. Against ships of changing course and speed, the weapon was useless. A message arrived at the Department of War. SMALL SPACE CRAFT DETACHED ITSELF FROM INVADING VESSEL AT INSTANT OF STRONG UNTUNED WAVE DISTURBANCE. SMALL CRAFT MAKING GUIDED FLIGHT TOWARD PLANET FOUR. WILL LAND ON DARK SIDE NORTHERN AREA FIRST CONTINENT. REQUEST ORDERS. The Department of War was newly organized and had not time to acquire traditions of pomposity and bureaucratic delay. Within minutes its orders went back: EVACUATE ALL POPULATION FROM AREA IN QUESTION. HAVE GROUND VEHICLES ATMOSPHERE FLIERS READY TO TEST ARMAMENT OF CRAFT. BROADCAST APPEAL FOR VOLUNTEERS, GIVING DUE WARNING OF PROBABLE DEATH. NO SPACE CRAFT TO BE USED. NO HINT OF ADEQUATE DEFENSES MUST BE GIVEN TO ENEMY UNTIL FULL-SCALE OPERATION BY ENTIRE SYSTEM. The population of the Masa Four had had one experience of invaders from beyond. Some twenty-five million citizens began a swift, orderly evacuation— as a precaution against the landing of an unarmed lifeboat. Buck waked from an uneasy doze when the lifeboat descended to the planet's dark side. Every observation device known to man was at work to gather information, but Buck was not interested in technicalities. He yawned elaborately, even as scanner beams were noted. He stretched as the scanner beams cut off abruptly. He shook himself comfortably as the analyzers reported the atmosphere to be Earth-type, with a considerable excess of the inert gases but well inside the comfort range of oxygen-nitrogen mixtures. The lifeboat went down carefully, feeling for dangers. Infrared equipment reported the shore of a sea and oddities that could be the equipment of a harbor. Maynard sheered the tiny craft away. He actually neared ground only a hundred-odd miles away. It was his job to get himself killed if the local population could manage it, but it was not his job to make them. If they knew the seeming comet out in space was a spaceship, they'd be on the alert. If they were the race that had murdered the Capellan colonists, they'd try to keep him from getting back to his ship. If they weren't— The lifeboat grounded with infinite caution in what the scanners declared was a jungle of feathery-leaved vegetation. For long, long minutes Maynard sat tense, prepared to fling the little craft skyward at any sign of action against it. Nothing happened. The outside microphones transmitted noises, to be sure, but they were the random sounds of wild jungle life. After a long time Maynard cracked a port. Still nothing. "If anybody wants to volunteer to get biological specimens," said Maynard, "he can step out. In case of alarm, though, I'm going to take this boat up and try to wriggle back—to find out what they'll try to use to stop us." ; Voices answered. There was the clanking of an unlocking door. Buck trotted back to it. Fascinating smells came in the opening. Men stepped out—armed and cautious. The exit door stayed open. One man stood by to shut and dog it if the lifeboat shot skyward. It took courage for men to venture out, knowing that they might have to be abandoned so the lifeboat's mission of drawing enemy fire—if this race was inimical—could be carried out. But Buck was fascinated by the smells. He would have liked to get back to Holden, of course, but these men were his friends, too. If they went out into this place of innumerable novel smells— He jumped lightly to the ground. His nose was in- stantly busy. The ground had a different smell from that of Earth. The plants were new. There were scents which must be animals, but not any animals Buck- had ever scented before. He heard a man moving nearby, taking samples of vegetation. Very much could be inferred from the types of starch and cellulose this planet's vegetation contained. But Buck could 'have told much more, from what his nose discovered. Here a little carnivore had trailed a skittering small thing which periodically darted up into overhanging vegetation, and as periodically darted down again. There a small herbivore had made a vast, terrified leap for no apparent reason—which meant that a flying thing had made a swoop at it, and missed. And here a thing which had almost the smell of a snake moved in distinctive hops, while there was a definite smell of a warm-blooded animal in something which left a completely continuous trail by traveling on its belly. Buck explored, utterly absorbed in this world of literally new smells. From time to time he heard the sounds made by the men, and was reassured. But he strayed farther and farther from the grounded lifeboat—only sometimes he stopped and listened to it— and he had found the burrow of some living creature and was sniffing absorbedly at its entrance when the really significant noises began. One noise began at the horizon and swept toward the zenith. It was a dull, humming rumble, like the motors of atmosphere fliers Buck had heard back on Earth. It was mechanical and, therefore, of man, and, therefore, not to be feared or suspected. At the same time there came distant clankings. And they were like bulldozers and other machines of men, and they were not to be feared, either. Buck sniffed fascinatedly at the burrow. Men's voices called sharply. Had Holden called him, Buck would have gone bounding instantly. But he owed a lesser obedience to other men. He sniffed again and again, lingeringly. Then, as he trotted unhurriedly in response to the call, he heard the zooming roar of a lifeboat drive in atmosphere. It shot toward the sky. It did not occur to Buck that he might have had to be left behind—as a man would have been abandoned under like circumstances—because the lifeboat had to test out the deadliness of armaments on this planet, but had to be aloft to test them fully. When he got back to the place where the lifeboat had been, though, it was gone. Buck was simply bewildered. The droning above frew to a thunderous, circling roar. There were many ying things overhead, and they cruised back and forth in the darkness in a pattern which would have made it difficult indeed for the lifeboat to have escaped without coming under radar-aimed fire. At the same time, the clanking mechanical noises came closer from at least three directions. Buck smelled incredulously at the place where the lifeboat had been but where it was no longer. He ran uneasily along the scent trails left by the men who had gathered biological specimens. It was completely unthinkable that the men had deserted him. He came back again and again to the place where the lifeboat had rested. He was unhappy, of course, but it was not possible for him-to imagine himself abandoned. He waited uncomfortably for the men to notice that he'd been left behind and to come back after him. Roarings circled in the overcast sky above him. Clankings approached in the encircling dark. Those were things of men—not his men, perhaps, but certainly men who would be friendly to a large, brown, well-mannered dog with a collar around his neck which said he belonged to Holden. They might even help him get back to Holden. But meantime he trotted uneasily about the place to which the lifeboat had not returned. The noises and clankings grew louder. When the noises were very near, a blindingly bright white light abruptly shone down from a low-flying plane which spun in dizzy tight circles overhead. The light showed everything with a pitiless clarity, and Buck blinked dazedly. But he was not alarmed. Machines and bright lights and flying things meant men. And a self-respecting dog has a perfectly comfortable relationship with all men, though it is a special relationship with the crew of his ship, and hi& tie to his master is unique. Buck moved prudently out of the way as machines with glaring lights came clanking through the jungle, thrusting aside the feathery trees with a powerful violence. He moved out of their path, but he did not dodge into the shadows. He blinked and wagged his tail abstractedly and prepared to greet the men in the machines with due courtesy. Of course they would help him get back to Holden! A machine stopped, and something got out of it. But the figure was not a man. Buck sniffed incredulously. Then his hackles rose. It was not possible! Machines were handled by men! Only by men! The Masan moved toward him. Buck growled warningly. Unbearable light smote upon him. He growled again, bristling, a big brown dog growling in warning that members of a mere race which might have been sniping Earth ships and massacring Earth colonies had better not bother him! Buck, of course, knew nothing of missing ships or massacres. He was a dog, a man's dog, and he could imagine no creature which was not inferior to man and which a man's dog could not reasonably defy. It was an extraordinary picture. Alien and unlikely jungle trees rising toward an overcast sky in which a bright white light whirled in dizzying circles. Huge, gleaming machines with lights—very bright lights— stabbing through the jungle's feathery leafage and casting innumerable sharp shadows. The Masans, inhabitants of the fourth planet of Masa Gamma—not too much unlike men, to be sure—staring at a place in the jungle where a ship's lifeboat had landed and where a big brown dog stood warningly at bay and growled at them of the wrath of his masters. There was a pause. A race which has space radios, and interplanetary ships, and radar, is not likely to be altogether stupid. And there were scanners in the ground vehicles, too, which carried back to record rooms everything the machines saw. The best brains of the race watched this meeting. And perhaps it was back where the scanned picture of the event was seen that someone realized that Buck's paws were not made for the handling of machinery or the making of spaceships. Or perhaps something more subtle— There were sounds which Buck somehow knew were language, though he could not understand them as words. He turned sedately from the first figure, which had halted at his growl. He blinked dignifiedly at the surrounding lights. None advanced toward him. Buck emitted sundry small, confident, admonitory rumblings. His men had been here. They had gone away. They would come back for him. Of course. He was going to wait for them. He was not arbitrary about it. He would allow the machines to pass as they pleased. Men probably wished the machines to do thus and so, and he would not interfere. But he would wait here. He deliberately turned himself around twice and lay down on the ground. But his head stayed erect and he blinked at the lights. He calmly and confidently settled down for men to notice that he'd been left behind and to come back for him. But he hoped desperately that Holden would be with them. A report went to the Department of War on Planet Four. It was a highly accurate report, covering the landing of a small space craft on the northern area of the First Continent. The footprints of men were accurately transmitted, as well as the impression left by the spaceboat in the soil. There were motion pictures of Buck. Most of the report, naturally, was about him. ". . . Limited but definite intelligence," said the re- port. "Is aware of social relationships neither hostile nor friendly, but tolerant. Is familiar with machines and regards them without fear but without interest. Has an extraordinary air of self-confidence and seems justified in opposing the wishes of more intelligent beings, though offering no hostility unless an attempt is made to force it to comply . . . Appears to be a member of a subject species to the makers of the space craft, though its utility is not clear, since it has neither prehensile claws nor any apparent technical aptitude for the supervision of machines .. . We are setting up psychoscanning devices to attempt to extract information from its memories, of course without its awareness of the process. Meanwhile we are making every effort to leave it emotionally undisturbed.. .." A later report: ". .. Psychoscanners have been able to secure excellent pictures and sound memories from the animal. It is of a species which lives in symbiosis with the creatures operating the space craft. Its utility to the superior race is not yet clear, but its subservience to them—they are not much unlike us—is proven by the records forwarded with this report. The animal's vision appears to be comparatively poor, but its hearing and smell are excellent. Its memories of smells, in particular, are especially vivid. We have vision-memory records of various members of the spaceship's crew, but smell-memories of every individual. Apparently, however, little or no technical information can be had from the animal because of the disinterest of the 'Buck'—this is the auditory memory of the animal's name for itself—in such matters. Memories of the naval base and of the presumed home planet of the invaders are concerned almost exclusively with smells. It is extremely concerned with trees and posts and the smells associated with them. . . . We regret that no useful technical information can be had. . . ." An order from the Department of War: URGENT. FIRST ATTENTION. THIS ORDER SUPERSEDES ALL OTHERS WHATSOEVER AND CLAIMS THE OBEDIENCE OF EVERY CITIZEN BEFORE ANY OTHER ACTIVITY WHATEVER. The Planetary Council has decided that information obtained from the Buck will determine our attitude toward the invaders. The fullest data must be secured concerning the relative loyalty of superior and inferior. Subject races can be psychologically conditioned to loyalty to tyrannical superiors. To what extent was this done to the Buck, and how? To what extent are rights conceded to the inferior race? What punishments are inflicted for mistakes of the race of inferior intelligence? What social stigma attaches to them? To what degree does the Buck expect loyalty to his kind from the superior race? What is the nature of the compact between the two—explicit or implied—and to what extent is it observed by the superior? What . . . The order continued in exhausting detail. It was based upon the realization that Buck—as a domestic animal—contained within his skull an absolutely objective picture of the human race. Buck would not be unbiased in his contemplation of his memories, but his memories would be right. A dog's-eye view of humanity would be, within its limits, an extraordinarily revealing view. The Planetary Council accepted the conclusion that no technical or military information could be had from Buck. But what information it could obtain would be priceless. No man could be truthful about his own race, talking to an alien entity. But a dog— The Planetary Council pushed its preparations for war. It had very little hope of anything but never-ending battle through all the centuries of the future. But what hopes it had were centered in Buck. Buck himself found life confusing. The place where the lifeboat had knded was fenced in now, and he was inside the fence. The things which were not men treated him with respect, and he treated them with the self-respecting courtesy of a well-mannered dog. They pointed things at him, and he was bored. But presently they had a loud-speaker which made noises. Once it barked at him in exact similitude of another dog—in fact, Buck remembered a dog at the Rigel base whose bark had sounded exactly like that. He barked back angrily. But the loud-speaker did not bark again. Another time, Holden's voice came out of it. And Buck leaped in frenzied joy, his tail wagging until it was almost a blur, and gave tongue in such howlings of heartbroken joy as a dog does give when his master returns after many days. When he realized that it was the loud-speaker, he could not accept the disappointment. He went whimpering about the enclosure, searching for Holden. There were other stimuli applied to Buck, too. One of the Masans brought him food. At first Buck sniffed at it gingerly. If he must eat of unfamiliar things, he preferred food of his own killing. But ultimately he tolerated the Masan and ate. The Masan had a loudspeaker attached to his body, and it said "Buck" on various occasions, and at first Buck's tail wagged joyously at the familiar syllable. But even when the Masan himself mastered the articulation of the name, Buck did not accept him fully. He wanted men. Especially, he wanted Holden. He dozed, and dreamed of Holden. He slept, and sometimes his dreams were such as to make his paws make tiny, jerking, frustrated movements, and sometimes he barked or whimpered or whined in his sleep. But the whinings were of the desperate joy he felt when in his dreams he saw Holden. He had no idea that the things pointed at him by the Masans made records of his memories as they were evoked by the increasing stock of stimuli the Masans were able to apply. Buck had understood the mean- ing of well over a hundred words, when combined with certain tones of voice. These words invariably provoked similar responses as the loud-speaker uttered them from the record of Buck's memories. While the preparations for the destruction of the Kennessee went on, the Masans studied Buck intensively. With their increasing comprehension of his brain, they tried to win his friendship. The one Masan assigned to the task tried painstakingly to fill the part of Holden. He used the memory-recordings of Hoi-den's voice. He tried to reproduce the strokings that Buck's memories said caused quiverings of ecstasy. Once he tried to tussle with Buck, as Holden did. And that took courage, because Buck was a big and powerful dog and the Masan was slight and relatively frail. But Buck would not play. He was polite and he was amiable within the limits a dog sets for himself toward other animals also useful to man—horses, for example, and cows and sheep and very occasionally a cat. But a dog will not play with a gamboling lamb nor run with a freed colt. Buck was reserved. His loyalty to man, and especially to Holden, could not be broken. And though he did eat, and condescendingly tolerated the Masan scientist—considered to have one of the two or three best brains in the system —who tried to replace Holden in his affections, he began to pine away as days and days passed by and began to stretch into weeks. He grew thin, though he was abstractedly aware that the people who were not men had begun very definitely to like him. After all, a man's dog doesn't thrive when he's separated from the man. The Kennessee rode on in the orbit it had chosen. Maynard had made an unhappy, abject apology to Holden for the desertion of Buck, and Holden accepted it, and neither of them felt at all better afterward. A man would have been left behind under exactly the same circumstances, but a dog is some- how different. He can't take care of himself. His abandonment couldn't be helped, but it rankled. The material brought back from Masa Four was duly examined. The space-radio records piled up, and electron-telescope examination of the planets continued, and evidences of a highly developed civilization accumulated—while scanner-beam observation of the Kennessee from Masa Four went on unendingly. It was a dubious situation extended almost to the breaking point. The lifeboat voyage had produced a reaction of ground vehicles and atmosphere fliers. It gave an impression of limited offensive power. But, on the other hand, there was interplanetary travel here. And the scanner beam on the Kennessee and the instant detection of the lifeboat was proof that the people of this system knew exactly what the Kennessee was. A civilization without defense weapons but with interplanetary ships and space radio should have tried to make contact with the Kennessee. If only to placate invaders, some attempt to open communication should have been made. Absence of such efforts was ominous. The appearance was that of a race which played possum until it could strike an overwhelming blow. So the Kennessee stayed in a state of nerve-racking alertness, with detectors out all around, and relays set to throw on overdrive should a high-velocity guided missile seem to draw near. "It looks bad," admitted the skipper to Holden. "We'd have tried to make contact, in their shoes. But whoever raided the Capella colony simply rode in and started killing. Maybe these people are that sort. Anyhow, if they do get us, our fleet will know who did it and come take them apart with planet-smasher bombs." Holden said dourly: "I wish I'd been in that lifeboat. When do we send back another message torp?" "We make no more landings," said the skipper. He added, "You'd never be able to find where the other boat landed, and anyhow Buck—" "Was probably blasted the instant they saw him," said Holden. He couldn't blame anybody, but he was angry. He missed Buck. On the twelfth day after Buck's landing, an interplanetary ship took off from Masa Four. The Ken-nessee had now ridden in beyond that planet and was headed for a perihelion point on the other side of Masa Gamma. If she survived to get there, it was the skipper's intention to put on overdrive and go back to base with all his records. But this interplanetary ship changed all plans. It appeared to be a rocket, in that it left behind a trailing cloud of vapor which looked like ejected gases. The spectroscopes, though, showed it to be merely hydrocarbon—smoke particles. And it altogether lacked the backward velocity which would have proved it a means of propulsion. It was simply a trail of vapor, as if for advertisement. In two days it had climbed well away from the planet and changed direction in a long smooth curve. The Navigation Officer came to the control room shortly after, to report that it was on an interception course, with interception speed, and would draw gradually closer to the Kennessee until contact was made. Then its trail of vapor broke, and swelled, and broke, and swelled, as if unmistakably to draw attention from the cruiser. The control-room loud-speaker boomed shortly. Holden's voice: "Sir!" he said harshly. "That phony rocket is beaming signals at us, running up and down the spectrum and trying frequency and amplitude modulation and everything else. Listen!" The speaker said resonantly: "Woof!" It was Buck's joyous bark. An instant later came the word "Buck" in a distorted but definitely recognizable version of Holden's own voice. And then, quite insanely, "Lie down, sir!" "Come get it boy!" "Fetch it, Buck," and all the other phrases to which the dog Buck had been trained to respond. As a means of opening communication between alien and mutually suspicious races, the vocabulary known to a big brown dog named Buck lacked dignity, but nothing could have been much more informative. "You see what it means, sir!" said Holden in a strained voice. "They got the stuff out of Buck's brain, somehow! They read his memories! They must have, somehow! They want to make contact!" Then he said thickly, "But if they killed him to rummage in his brain—" "Mr. Holden," said the skipper, "answer them, please. Speak as if to Buck himself, and see what happens." In the speaker in the control room he heard Holden's voice as he spoke into another microphone. "Buck!" said Holden hoarsely. "If you hear me, speak up boy! Buck! Do you hear me?" And then the loud-speaker bellowed with the joyous uproar with which Buck replied to his master. He barked and bayed and yelped and whined all at once, and then barked crazily like a creature gone quite mad with joy. "He ... he heard me, sir," said Holden unsteadily. "They didn't hurt him! I ... I think, sir—" "Quite so, Mr. Holden," said the skipper sedately. "I was about to order you to take a lifeboat and take another chance to learn something of these people. Suppose you go over and make contact with them? A race which knows a good dog when it sees one, and is honest enough to return him to his master, can't be the race that massacred half a million people on Capella Three!" The Masan scientist who'd tried to replace Holden in Buck's affections nevertheless grew rather friendly with Holden after the Kennessee landed on Masa Four. A message torp, sent back to base, had explained the situation and the reason for friendly contact with the Masan civilization. Of course, if the Kennessee vanished, the Masans would be known to be definitely responsible, but that did not seem to bother them. And it did not bother the humans, either. The Masan scientist explained to Holden: "It has worked out very well. With your atomic power, you can put any amount of energy into the power beam we've showed you, for battle with our common enemy. It is odd that we made power beams to fuel our interplanetary ships because we didn't have atomic energy, and you made atomic energy because you didn't have power beams!" "There'll be a lot of stuff that will fit together like that," said Holden. "Our civilization will mesh nicely, as long as we trust each other." "Yes," said the Masan, somehow ruefully. "We intended to blast you to atoms, because we were afraid, and you intended to destroy our planets, because you were, also. I think both our races owe much to Buck" "I still," said Holden uncomfortably, "can't see how you were able to trust us so completely. I don't think we'd have trusted strangers as you do us. Just because of Buck—" "But it is because of Buck," said the Masan wisely. "We could extract all of his memories. All of them. His kind adores men. He would accept any cruelty from you. But you are not cruel. He would give his life gladly, but no man would ask it. He is yours, unreservedly, but you do not accept from him without giving in return. Do you know when the policy of the Planetary Council, to trust men without limit, was finally decided?" "Why . . . no," said Holden. "When you entered the airlock of our ship," said the Masan, smiling, "and Buck met you. He had told us every secret he could impart. He had been almost a traitor, without knowing it. He had told us every- thing he knew of men. But when you entered our ship he leaped joyfully at you and you rolled on the floor together—you hugged him! You did not think of possible harm he had done. You were as glad to see him as he was to see you. That was when our policy was decided. Then we knew that men will always repay trust with loyalty." Then the Masan added, "That is, most men." Holden said uncomfortably: "Well—that's something that has worried the skipper. You people act as if all of us were as decent as our dogs think us. We aren't. You'll have to be ... well ... a little cagey, sometimes . . ." "So," said the Masan, "we learned from Buck. But also we learned that there will always be men to trust." Buck came dashing madly up the dark-green lawn. Holden and the Masan scientist sat on a sort of terrace of the Masan's home. Buck came racing up, panting happily, and thrust his muzzle into Holden's hand. He gave the Masan a brief tail-wag and went dashing off again. "That," said the Masan, "is something he would never do to me, though I ... yes ... I think I like him as much as you do." "That's because he's my dog," said Holden. "But he treats you like a man. Didn't you notice?" "True! I had not realized! But it is true! Listen! We must have dogs, we Masans! Dogs to like us as they like men! And then no man who likes dogs can ever distrust a Masan who likes them also, and no Masan—" The Masan laughed. "We could not despise a man an honest dog had for a master! Our two races will be brothers!" That is all of the story about this one part of the hunt for the Space Assassins. Everybody knows that their home system was found, and everybody knows that when we tried to open negotiations with them their ships attacked us in a raging ferocity, and that there was no possible end to it but the extermination of men—and Masans—or of the Assassins. The battle was the first that was ever fought with power beams in Earth ships with Masan gunners. That's history that everybody knows. But not everybody knows that there is a statue of Buck before the Planetary Council building on Masa Four. The Masans think it quite natural. They like dogs enormously, and dogs like them, too. The Masans already have a proverb that a dog is a Masan's best friend. There's no statue of Buck on Earth, though. But he doesn't mind. Buck is a very happy dog. He's with Holden. He follows him everywhere.