ead pounding and thick. In all of them there were objects, machines, gadgets things; some of them still purring or ticking quietly to themselves, some flickering with a ceaseless rainbow of lights. He could not stay in those places, because there was no food or water, and he could not find what he most sought. There were no real weapons. Perhaps the Heechee had not needed them. But there was one machine that had a gate of metal strips at one side and, when he wrenched them away, it did not blow up or electrocute him, as he had half thought it would. And he had a spear. And half a dozen times he encountered what looked like smaller, more complicated versions of the Heechee tunnelers. And some of them still worked. When the Heechee built they built forever. It took Paul three frightened, thirsty, baffling days of experiment to make any of them function, stopping to creep back to the gold corridors or the ship for food and water, always sure that the thundering noise of the machine would draw the Old Ones down on him before he was ready. But it did not. He learned to squeeze the nipple that hung down from the steering yoke to make the ready lights spring into life, to shove the ponderous knurled wheel forward or back to make it advance or retreat, to tread on the oval floorplate that caused the blue-violet glow to lance out before the machine, softening even the Heechee metal it touched. That was the noisy part. Paul feared greatly that he would destroy something that would wreck Heechee Heaven itself, if he did not bring down a search party. When he came to move the machine to the place he had picked out it was almost quiet, oozing forward on its rollogons. And he stopped to consider. He knew where the Old Ones went, and when. He had a spear that could kill a single Old One, maybe could let him defeat even two or three if he came on them by surprise. He possessed a machine that could annihilate any number of Old Ones, if he could only get them to mass in front of it. It all added up to a strategy that might even work. It was chancy-oh, God, it was chancy! It depended on at least half a dozen trials by combat. Even though the Old Ones did not seem to seek him armed, who was to say that they might not learn? And what arms might they have? It meant killing some of them, one by one, so expertly and carefully that he did not attract the attention of the whole tribe until he was ready for it-and then attracting them all at once, or so large a majority of them that he could handle the rest with his spear. (Was that really a good gambling bet?) And, above all, it meant that the Oldest One, the great machine Paul had only glimpsed once or twice at long range and about whose powers he knew nothing, must not intervene, and how likely was that? He had no sure answers. He did have hopes. The Oldest One was too large to move easily through any of the corridors but the gold-skeined ones. Nor did it seem to move frequently at all. And perhaps he could somehow trick it, too, before the devouring haze of the tunneling machine-which could not, in this place, really be a tunneling machine, but seemed to work in about the same way. At every step the odds were against him, true. But at every step there was at least a slim chance for success. And it was not the risk that stopped him at the last. The Paul Hall who stole about and schemed in the tunnels of Heechee Heaven, half crazed with anger and fear and worry for his wife and the others, was not entirely crazy. He was the same Paul Hall whose gentleness and patience had made Dorema Herter marry him, who had accepted her saucy, sometimes bratty little sister and abrasive father as part of the bargain. He wanted very much to save them and bring them to freedom. Even at risk. There was always a way out of the risk for him, if only to crawl aboard Wan's ship and return to the Food Factory and thus-slowly, alone and mournful, but safe-ultimately to Earth and wealth. But, apart from risk, what was the cost? The cost was wiping out perhaps an entire population of living and intelligent creatures. They had taken his wife from him, but they had not really harmed her. And, try as he would, Paul could not convince himself he had the right to exterminate them. And now here was this "rescuer," this nearly dead castaway named Robin Broadhead, who listened sketchily to Paul's plan and smiled loftily and said, politely enough, "You're still working for me, Hall. We'll do it my way." "The hell we will!" Broadhead stayed polite enough, and even reasonable-it was amazing what a bath and a little food had done for him. "The key," he said, "is to find out what we're up against. Help me lug this information-processing stuff to where the Dead Men are, and we'll take care of that. That's the first thing." "The first thing is rescuing my wife!" "But why, Hall? She's all right where she is-you said so yourself. I'm not talking about forever. One day, maybe. We find out what we can from the Dead Men. We tape it all, pump them dry if we can. Then we take the tapes and stick them in my ship, and then..." "No." "Yes!" "No, and keep your God-damned voice down!" They squared off like kids in a schoolyard, both flushed and furious, their eyes locked. Until Robin Broadhead grimaced and shook his head and said, "Oh, hell. Paul? Are you thinking what I'm thinking?" Paul Hall let himself relax. After a second he said, "Actually, I'm thinking the two of us would do better to figure out what is the best thing to do, instead of arguing about who makes the decision." Broadhead grinned. "That was what I was thinking, all right. You know what my trouble is? I'm so surprised to be still alive that I don't know how to adjust to it." It only took them six hours to haul and set up the PMAL-2 processor where they wanted it, but it was six hours of hard work. They were both near the frayed end of exhaustion and it would have made sense to sleep, but they were itching with impatience, both of them. Once they had the main power source connected to the program banks Albert's prerecorded voice instructed them, step by step, on how to do the rest-the processor itself sprawled across the corridor, the voice terminals inside the Dead Men's chamber, next to the radio link. Robin looked at Paul, Paul shrugged to Robin, Robin started the program. From just outside the door they could hear the flat, wheedling voice from the terminal: "Henrietta? Henrietta, dear, can you answer me?" Pause. no answer. The program Albert had written with Sigfrid von Shrink's help tried again: "Henrietta, it's Tom. Please speak to me." It would have been faster to punch out Henrietta's code to attract her attention, but harder to square with the pretense that her long-lost husband had reached her from some faroff outpost by radio. The voice tried again, and once more. Paul scowled and whispered, "It isn't working." "Give it a chance," Robin said, but not confidently. They stood there nervously, while the dead computer voice pleaded. And then at last, a hesitant voice whispered, "Tom? Tomasino, is that you?" Paul Hall was a normal human being, squashed a little out of shape, perhaps, from four years of imprisonment and a hundred days of flight and fright. Normal enough, though, to share the normal prurience; but what he heard was more than he wanted to hear. He grinned in embarrassment at Robin Broadhead, who shrugged uneasily back. The hurt tenderness and spiteful jealousy of other people is humiliating to hear and can only be eased by laughter; the divorce detective passes around his bootleg tape of a wired bed for comic relief on a slow day at the office. But this was not comic! Henrietta, any Henrietta, even the machine revenant called Henrietta was not funny in her moment of heart's-desire, when she was being gulled and betrayed. The program that wooed her was skillfully done. It apologized and begged, and it even sobbed, in rustly tape-hissing sobs, when Henrietta's own flat tape voice broke with sobs of spent sadness and hopeless joy. And then, as it had been programmed to do, it settled in for the kill. Would you. Dear Henrietta, could you... Is it possible for you to tell me how to operate a Heechee ship? Pause. Hesitation. Then the voice of the dead woman said: "Why-yes, Tomasino." Another pause. It lengthened itself, until the programmed deceiver moved in to fill the gap: "Because if you could, dear, I think I might be able to join you. I'm in a sort of a ship. It has a control room. If I knew how to work it..." It was incredible to Paul that even a poorly stored machine intelligence could succumb to such transparent blandishments. Succumb Henrietta did. It was repellent to him to take part in the fraud, but take part he did, and once started Henrietta could not be stopped. The secret of controlling the Heechee ships? Of course, dear Tomasino! And the dead woman warned her fake lover to stand by for burst transmission and hurled out a whistling crackle of machine talk of which Paul could not understand a sound and in which he could not find a word; but Robin Broadhead, listening to the private status-report voice of the computer on his headset, grinned and nodded and held up thumb and forefinger in a circle of success. Paul signed silence and pulled him down the corridor. "If you've got it," he whispered, "let's get out of here!" "Oh, I've got it!" chortled Robin. "She's got it all! She was in open circuit with whatever kind of machine runs this thing, it picked her brains and she picked its, and she's telling the whole thing." "Great. Now let's find Lurvy!" Broadhead looked at him, not angry but pleading. "Just a few more minutes. Who knows what else she got?" "No!" "Yes!"-and then they looked at each other, and shook their heads. "Compromise," said Robin Broadhead. "Fifteen minutes, all right? And then we go rescue your wife." They edged back along the corridor with smiles of rueful satisfaction on their faces; but the satisfaction drained. The voices were not embarrassingly intimate now. They were worse. They were almost quarreling. There was somehow a snap and a snarl in the flat metallic voice that said, "You're being a pig, Tom." The program was cloyingly reasonable: "But, Henrietta, dear, I'm only trying to find out..." "What you try to find out," grated the voice, "depends on what your capacities to learn are. I'm trying to tell you something more important! I tried to tell you before. I tried to tell you all the while we were coming out here, but, no, you didn't want to hear, all you wanted was to get off in the lander with that fat bitch..." The program knew when to be placatory. "I'm sorry, Henrietta, dear. If you want me to learn some astrophysics I will." "Damn right you will!" Pause. "It's terribly important, Tom!" Pause. And then: "We go back to the Big Bang. Are you listening, Tom?" "Of course I am, dear," said the program in its humblest and most endearing way. "All right! It goes back to how the universe got started, and we know that pretty well-with one little hazy transition point that's a little obscure. Call it Point X." "Are you going to tell me what 'Point X' is, dear?" "Shut up, Tom! Listen! Before Point X, essentially the whole universe was packed into a tiny glob, no more than a matter of kilometers through, super-dense, super hot, so squeezed it had no structure. Then it exploded. It began to expand-up to Point X, and that part is pretty clear. Do you follow me so far, Tom?" "Yes, dear. That's basically simple cosmology, isn't it?" Pause. "Just pay attention," Henrietta's voice said at last. "Then, after Point X, it continued to expand. As it expanded, little bits of 'matter' began to condense out of it. First came nuclear particles, hadrons and pious, electrons and protons, neutrons and quarks. Then 'real' matter. Real hydrogen atoms, then even helium atoms. The exploding volume of gas began to slow. Turbulence broke it into immense clouds. Gravity pulled the clouds into clumps. As they shrank the heat of contraction set nuclear reactions going. They glowed. The first stars were born. The rest," she finished, "is what we can see going on now." The program picked up its cue. "I see that, Henrietta, yes. How long are we talking about, now?" "Ah, good question," she said, in a voice not at all complimentary. "From the beginning of the Big Bang to Point X, three seconds. From Point X to right now, about eighteen billion years. And there we have it." The program was not written to deal with sarcasm, but even in the flat metal voice sarcasm hung. It did its best. "Thank you, dear," it said, "and now will you tell me what is special about Point X?" "I would tell you in a thick minute, my darling Tomasino," she said sunnily, "except that you are not my darling Tomasino. That ass-head would not have understood one word of what I just said, and I don't like being lied to." And no matter what the program tried, not even when Robin Broadhead dropped the pretense and spoke to her direct, Henrietta would say no more. "Hell with it," said Broadhead at last. "We've got enough to worry about in the next couple of hours. We don't have to go back eighteen billion years for it." He hit a pressure release on the side of the processor and caught what came out: the thick, soft rag-flop tape that had caught everything Henrietta had said. He waved it aloft. "That's what I came for," he said, grinning. "And now, Paul, let's take care of your little problem-and then go home and spend our millions!" In the deep, restless sleep of the Oldest One there were no dreams, but there were irritations. The irritations came faster and faster, more and more urgent. From the time the first Gateway prospectors had terrifyingly come until he had written (he thought) the last of them off, only the wink of an eye-not more than a few years, really. And until the strangers and the boy were caught, hardly a heartbeat; and until he was awakened again to be told the female had escaped no time at all-none! Hardly even time for him to decouple sensors and effectors and settle down; and now there was still no peace. The children were panicked and quarrelsome. It was not their noise alone that disturbed him. Noise could not awaken the Oldest One; only physical attack, or being addressed directly. What was most irritating about this racket was that it was not quite addressed to him, but not quite not, either. It was a debate-an argument; a few frightened voices demanding he be told something at once, a few even more frightened ones pleading against it. And that was incorrect. For half a million years the Oldest One had trained his children in manners. If he was needed, he was to be addressed. He was not to be awakened for trivial causes, and certainly not by accident. Especially now. Especially when each effort of waking was more of a drain on his ancient fabric and the time was in sight when he might not wake at all. The fretful rumpus did not stop. The Oldest One called on his external sensors and gazed upon his children. Why were so few of them there? Why were nearly half of them sprawled on the floor, evidently asleep? Painfully he activated his communications system and spoke: "What is happening?" When, quailing, they tried to answer and the Oldest One understood what they were saying, the bands of color on his shell raced and blurred. The female not recaptured. The younger female and the boy gone too. Twenty more of the children found hopelessly asleep, and scores of others, gone to search the artifact, not reporting back. Something was terribly wrong. Even at the very end of its useful life the Oldest One was a superb machine. There were resources seldom used, powers not tapped for hundreds of thousands of years. He rose on his rollogons to tower over the quaking children and reached down into his deepest and least-used memories for guidance and knowledge. On his foreplate, between the external vision receptors, two polished blue knobs began a faint drone, and atop his carapace a shallow dish glowed with faint violet light. It had been thousands of years since the Oldest One had used any of his more punitive effectors, but as information from the great stores of memories gathered he began to believe that it was time to use them again. He reached into the stored personalities, even, and Henrietta was open to him; he knew what she had said, and what the new interlopers had asked. He understood (what Henrietta had not) the meaning of the hand weapons Robin Broadhead had been waving around; in the deepest of all memories, the ones that went back even before his own flesh-and-blood life, there was the lance that made his own ancestors go to sleep, and this was clearly much the same. Here was trouble on a scale he had never known before, of a kind he could not readily cope with. If he could get at them... But he could not. His great bulk could not travel through the artifact's passages, except the gold-skeined ones; the weapons that were ready to destroy would have no targets. The children? Yes, perhaps. Perhaps they could hunt out and overcome the others; certainly it was worth the effort to order them to do so, the few survivors, and he did. But in the rational, mechanical mind of the Oldest One the capacity for computation was unimpaired. He could read the odds well. They were not good. The question was, was his great plan endangered? The answer was yes. But there, at least, there was something he could do. The heart of the plan was the place where the artifact was controlled. It was the nerve center of the entire construct; it was where he had dared to set in motion the final stages of his plan. Before he had finished framing the decision he was acting it out. The great metal bulk shifted and turned, and then rolled out across the spindle, into the wide-mouthed tunnel that led to the controls. Once there, he was secure. Let them come if they chose! The weaponry was ready. Its great drain on his dwindling powers was making him slow and unsteady to move, but there was power enough. He could blockade himself and let the flesh-and-blood things settle things however they might, and then... He stopped. Ahead of him one of the wall-aligning machines was out of place. It sat squarely in the center of the corridor, and behind it... If he had been just a trifle less drained, the fraction of a second faster.... But he was not. The glow from the wall aligner washed over him. He was blind. He was deaf. He felt the external protuberances burn off his shell, felt the great soft cylinders he rolled on melt and stick. The Oldest One did not know how to feel pain. He did know how to feel anguish of the soul. He had failed. The flesh-and-blood things had control of his artifacts, and his plans were at an end forever. 16 The Richest Person There Is My name is Robin Broadhead, and I am the richest person there is in the whole solar system. The only one who comes close is old Bover, and he would come a lot closer if he hadn't thrown half of his money into slum clearance and urban rehabilitation and a lot of what was left into an inch-by-inch scan of trans-Plutonian space, looking for the ship with what was left of his wife, Trish. (What he is going to do with her if he finds her I can't imagine.) The surviving Herter-Halls are also filthy with money. That's a good thing, especially for Wan and Janine, who have a complicated relationship to sort out, in a complicatedly unwelcoming world. My wife, Essie, is in the best of health. I love her. When I die, that is, when even Full Medical can't patch me up any more, I have a little plan about how to deal with someone else I love, and that satisfies me. Almost everything satisfies me. The only exception is my science advisor, Albert, who keeps trying to explain Mach's Principle to me. When we took over Heechee Heaven, we got it all. The way to control Heechee ships. The way to build Heechee ships, including the theory that makes it possible to go faster than light. No, it doesn't involve "hyperspace" or the "fourth dimension". It is very simple. Acceleration multiplies mass, so says Einstein-the real one, not Albert. But if the rest mass is zero it does not matter how many times you multiply it. It remains zero. Albert says that mass can be created, and proves it by basic logical principles: it exists, therefore it can be created. Therefore it can be eliminated, since what can be made to be can also be made to stop being. That is the Heechee secret, and with Albert's help to set up the experiment, and Morton's help to coerce the Gateway Corp into making ships available, we tried it out. It didn't cost me a cent; one of the advantages of great wealth is that you don't have to spend it. All you have to do is get other people to spend it for you, and that's what law programs are for. So we sent two Fives out at once from Gateway. One was on lander power only, and it contained two people and a cylinder of solid aluminum with strain detectors attached. The other held a full crew, ready for an actual mission. The instrument ship had a live camera pickup with an image split three ways: one on the gravity meter, one on the second ship, one on a cesium-atom digital clock. To my eyes the experiment didn't show a thing. The second ship began to disappear, and the gravity meter recorded its disappearance. Big deal! But Albert was elated. "Its mass began to disappear before it did, Robin! My God. Anyone could have tried that experiment any time in the last dozen years! There's going to be at least a ten-million-dollar science bonus for this!" "Put it in petty cash," I said, and stretched, and rolled over to kiss Essie, because we happened to be in bed at the time. "Is very interesting, dear Robin," she said drowsily, and kissed me back. Albert grinned and averted his eyes, partly because Essie has been tinkering with his program and partly because he knew as well as I did that what she said was politely untrue. Astrophysics did not much interest my Essie. What interested her was the chance to play with working Heechee machine intelligences, and that interested her very much. Eighteen hours a day much, until she had tracked down all the major systems in what was left of the Oldest One, and the Dead Men, and the Dead Non-Men whose memories went back to an African savannah the better part of a million years ago. Not that she cared a lot about what was in the memories; but how it was there was her very business, at which she was very good. Reshuffling my Albert program was the least of what Essie got out of Heechee Heaven. What we all got was a very great deal indeed. The grand charts of the Galaxy, showing everywhere the Heechee had been. The grand charts of black holes, showing where they are now. Even where Kiara is. As one tiny fringe benefit, I even got the answer to one question that on a purely subjective level had been interesting me very much: why was I still alive? The ship that carried me to Heechee Heaven had flipped over into deceleration mode after nineteen days. By all the laws of parity and common sense, that meant it would not arrive for another nineteen, by which time I should have been surely dead; but in fact it docked in five. And I wasn't dead at all, or not quite; but why? Albert gave me the answer. Every flight ever successfully completed in a Heechee ship had been between two bodies that, relatively, were more or less at rest-a few tens or at most a few hundreds of kilometers a second difference in their relative velocities. no more. Not enough to make a difference. But my flight had been pursuing an object itself in very rapid motion. It had been almost all acceleration. The slowdown had taken only a tiny fraction of the speedup. And so I lived. And all that was very satisfying, and yet... And yet there is always a price. There always has been. Every big jump forward has carried a hidden cost, all through history. Man invented agriculture. That meant someone had to plant de cotton and someone had to hoe de corn. And dat's how slavery was born. Man invented the automobile, and got a dividend of pollution and highway death. Man got curious about the way the sun shines, and out of his curiosity came the H-bomb. Man found the Heechee artifacts and tracked down some of their secrets. And what did we get? For one thing, we got Payter, almost killing a world, with a power no one had ever had before him. For another we got some brand-new questions, the answers to which I have not yet quite nerved myself up to face. Questions that Albert wants to try to answer, about Mach's Principle; and that Henrietta raised, with her talk about Point X and the "missing mass". And a very big question in my own mind. When the Oldest One broke Heechee Heaven out of its orbit and sent it flying through space toward the core of the Galaxy what, exactly, was he heading toward? The scariest, I guess, and also the most satisfying, I know, moment of my life was when we had burned the feelers off the Oldest One and, armed with Henrietta's instructions, sat down before the control board of Heechee Heaven. It took two to make it move. Lurvy Herter-Hall and I were the two most experienced pilots present-if you didn't count Wan, who was off with Janine, rounding up the waking Old Ones to tell them there had been a change in government. Lurvy took the right-hand seat and I took the left (wondering a lot just what strange-shaped butt had first sat in it). And there we went. It took more than a month to get back to orbiting the Moon, which was the point I had picked out. It wasn't a wasted month, there was plenty to do on Heechee Heaven; but it went pretty slowly, because I was in a very big hurry to get home. It took all the nerve I had to squeeze that teat, but, you know, it wasn't all that hard. Once we understood that the main bank of controls carried the codes for all the preset objectives-there are more than fifteen thousand of them, all over the Galaxy and some outside-it was just a matter of knowing which code was which. Then, all of us really delighted with ourselves, we decided to show off. We got a squawk from the radio-astronomers on the far side because our circumlunar orbit was getting in the way of their dishes every time we came around. So we moved. You do that with the secondary boards, the ones no one has ever dared to touch in midflight and that don't seem to do much on the original launch. Main boards, preprogrammed objectives; secondary boards, any point you want, provided you can spell out its galactic coordinates. But the joker is that you can't use the secondary boards until you've nulled the primaries by setting them all down to zero-that translates to a clear deep red color on each-and if any prospector ever happened to do that on his own, he lost his programming to get back to Gateway. How simple everything is once you know. And so we put that big son-of-a-bitching artifact, half a million metric tons of it, in close Earth orbit, and invited company. The company I wanted most was my wife. What I wanted next was my science program, Albert Einstein-that's not really a reflection on Essie, you know, because she wrote him. It was a tossup whether I went down to her or she came up to me, but not in her mind. She wanted to get her hands On the machine intelligences in Heechee Heaven, I would judge, at least as much as I wanted to get mine on her. In a 100-minute Earth orbit the transmission time isn't bad, anyway. As soon as we were in range the machine Albert had programmed for me was talking to him, pumping everything it had learned into him, and by the time I was ready to talk to him he was ready to talk back. Of course it wasn't the same. Albert in full three-dimensional color in the tank at home was a lot more fun to chat with than black-and-white Albert on a flat plate in Heechee Heaven. But until some new equipment came up from Earth that was all I had, and anyway it was the same Albert. "Good to see you again, Robin," he said benevolently, poking the stem of his pipe toward me. "I guess you know you have about a million messages waiting for you?" "They'll wait." Anyway, I had already had about a million, or it seemed that way. What they mostly said was that everybody was annoyed but, in the long run, delighted; and I was once again very rich. "What I want to hear first," I said, "is what you want to tell me." "Sure thing, Robin." He tapped out his pipe, regarding me. "Well," he said, "technology first. We know the general theory of the Heechee drive, and we're getting a handle on the faster-than-light radio. As to the information-handling circuits in the Dead Men and so on-as I am sure you know," he twinkled, "Cospozha Lavorovna-Broadhead is on her way to join you. I think we may confidently expect considerable progress there, very quickly. In a few days a volunteer crew will go to the Food Factory. We are pretty sure it, too, can be controlled, and if so it will be brought into some nearby orbit for study and, I think I can promise, duplication. I don't suppose you want to hear about minor technology in detail just now?" "Not really," I said. "Or not right at this minute." "Then," he said, nodding as he filled the pipe again, "let me get to some theoretical considerations. First there is the question of black holes. We have unequivocally located the one your friend, Gelle-Klara Moynlin, is in. I believe it would be possible to send a ship there with reasonable assurance that it would arrive without serious damage. Return, however, is another question. There appears to be nothing in the Heechee stores that gives us a cookbook recipe for getting anything out of a black hole. Theory, yes. But if one should desire to convert the theory into practice that will require R&D. A lot of it. I would hesitate to promise results in less than, say, a matter of years. More likely decades. I know," he said, leaning forward earnestly, "that this is a matter of personal importance to you, Robin. It also may be a matter of grave importance to all of us, by which I mean not only the human race but machine intelligences as well." I had never seen him look so serious. "You see," he said, "the destination of the artifact, Heechee Heaven, has also been unequivocally identified. May I show you a picture?" That was rhetoric, of course. I didn't reply, and he didn't wait. He shrank down into a corner of the flatplate screen while the main picture appeared. It was a wash of white, shaped like a very amateurishly drawn Turkish crescent. It was not symmetrical. The crescent was off to one side, and the rest of the picture was black except for an irregular sprinkle of light that completed the horns of the crescent and protracted them into a hazy ellipse. "It is too bad you cannot see this in color, Robin," said Albert, squinting up from his corner of the screen. "It is blue rather than white. Shall I tell you what you are seeing? It is orbiting matter around some very large object. The matter to your left, which is coming toward us, travels fast enough to emit light. The matter to the right, which is going away, travels more slowly relative to us. What we are seeing is matter turning into radiation as it is drawn into an extremely large black hole, which is located at the center of our Galaxy." "I thought the speed of light was not relative!" I snapped. He expanded to fill the screen again. "It is not, Robin, but the orbit velocity of the matter which produces it is. That picture is from the Gateway file, and until just recently it was not located in space. But now it is clear that it is at, indeed that in a sense it forms, the galactic core." He paused while he lit his pipe, looking at me steadily. Well, that's not quite true. There was the split-second lag, and even Albert's circuits couldn't do anything about it; if I moved his gaze lingered where I had been for just long enough to be disconcerting. I didn't rush him, and when he had finished puffing the pipe alight he said: "Robin, I am often unsure of what information to volunteer to you. If you ask me a question, that's different. About any subject you suggest, I will tell you as much of what I know as you will listen to. I will also tell you what may be so, if you ask for a hypothesis; and I will volunteer hypotheses when, according to the constraints written into my program, that seems appropriate. Gospozha Lavorovna-Broadhead has written quite complex normative instructions for this sort of decision-making, but, to simplify, they come down to an equation. Let V represent the 'value' of a hypothesis. Let P represent its probability of being true. If I can complete the sum of VP so that it equals at least one, then I should, and do, volunteer the hypothesis. But, oh, Robin, how hard it is to assign the correct numerical values to P and V/In the specific case now at issue I cannot be in any way sure of any value I can give its probability. But its importance is very high. To all intents, it might as well be regarded as infinite." By then he had me sweating. What I know for sure about Albert's programming is that the longer he takes to tell me something, the less he thinks I am going to like hearing it. "Albert," I said, "get the hell on with it." "Sure thing, Robin," he said, nodding, but unwilling to be rushed, "but let me first say that this conjecture satisfies not only known astrophysics, although on a rather complex level, but also some other questions, e. g., where Heechee Heaven was going when you turned it around and why the Heechee themselves disappeared. Before I can give you the conjecture I must review four main points, as follows. "One. The quantities Tiny Jim referred to as 'gosh numbers'. These are numerical quantities, mostly of the sort called 'dimensionless' because they are the same in any units you measure. The mass ratio between the electron and the proton. The Dirac number to express the difference between electromagnetic and gravitational force. The Eddington fine-structure constant. And so forth. We know these numbers to great precision. What we do not know is why they are what they are. Why shouldn't the fine-structure constant be, say, 150 instead of 137-plus? If we understood astrophysics-if we had a complete theory-we should be able to deduce these numbers from the theory. We do have a good theory, but we can't deduce the gosh numbers from it. Why? Is it possible," he asked gravely, "that these numbers are in some way accidental?" He paused, puffing on his pipe, and then held up two fingers. "Two. Mach's Principle. This also turns Out to be a question, but perhaps a somewhat easier one. My late predecessor," he said, twinkling a little-I think to reassure me that this was, indeed, easier to handle-"my late predecessor gave us the theory of relativity, which is commonly understood to mean that everything is relative to something else excepting only the velocity of light. When you are at home on Tappan Sea, Robin, you weigh about eighty-five kilograms. That is to say, that is a measure of how much you and the planet Earth attract each other; it is your weight, in a sense, relative to the Earth. We also have a quality called 'mass'. The best measure of 'mass' is the force necessary to accelerate an object, say you, from a state of rest. We usually consider 'mass' and 'weight' to be about the same, and on the surface of the Earth they are, but mass is supposed to be an intrinsic quality of matter, while weight is always relative to something else. But," he twinkled again, "let's do a gedanke-experiment, Robin. Let's suppose that you're the only thing in the universe. There's no other matter. What would you weigh? Nothing. What would your mass be? Ah, that's the question. Let's suppose you have a little rocket-belt and you decided to accelerate yourself. You then measure the acceleration and compute the force to move you, and you come out with your mass-do you? No, Robin, you do not. Because there is nothing to measure movement against! 'Moving', as a concept, is meaningless. So mass itself-according to Mach's Principle-depends on some external system, Mach thought it might be what he called 'the entire background of the universe', to be meaningful. And according to Mach's Principle, as my predecessor and others extended it, so do all the other 'intrinsic' characteristics of matter, energy and space... including the 'gosh numbers'. Robin, am I wearying you?" "You bet your ass you are, Albert," I snarled, "but go ahead!" He smiled and held up three fingers. "Three. What Henrietta called Point X'. As you remember, Henrietta failed her doctoral defense, but I have made a study of her dissertation and I am able to say what she meant by it. For the first three seconds after the Big Bang, which is to say the beginning of the universe as we now know it, the entire universe was relatively compact, exceedingly hot, and entirely symmetrical. Henrietta's dissertation quoted at length from an old Cambridge mathematician named Tong B. Tang and others; the point they made was that after that time, after what Henrietta called 'Point X', the symmetry became 'frozen'. All the constants we now observe became fixed at that point. All the gosh numbers. They did not exist before 'Point X'. They have existed, and are unchangeable, ever since. "So at Point X in time, three seconds after the beginning of the Big Bang, something happened. It may have been some quite random event-some turbulence in the exploding cloud. "Or it may have been deliberate." He stopped and smoked for a while, watching me. When I did not react he sighed and held up four fingers. "Four, Robin, and the last. I do apologize for this long preamble. The final point in Henrietta's conjecture had to do with 'missing mass'. There simply does not appear to be enough mass in the universe to fit the otherwise very successful theories of the Big Bang. Here Henrietta made an immense leap in her doctoral dissertation. She suggested that the Heechee had learned how to create mass and destroy it-and in this, as we now know, she was correct, although it was only a guess on her part, and the seniors before whom she conducted the defense of her dissertation were very quick to challenge it. She then made a further leap. She suggested that the Heechee had, in fact, caused some mass to disappear. Not on a ship, although if she had guessed that she would have been correct. On a very large scale. On a universe-wide scale, in fact. She conjectured that they had studied the 'gosh numbers' as we have, and come to certain conclusions which seem to be true. Here, Robin, it gets a little tricky, so pay close attention-but we are almost home. "You see, these fundamental constants like the 'gosh numbers' determine whether or not life can exist in the universe. Among very many other things, to be sure. But if some of them were a little higher or a little lower, life could not exist. Do you see the logical consequence of that statement? Yes, I think you do. It is a simple syllogism. Major premise, the 'gosh numbers' are not fixed by natural law but could have been different if certain different events had taken place at 'Point X'. Minor