Vargen frowned. Yoran's reply had been scoffingly obvious. Vargen's brow cleared. Laurice saw he was willing to overlook the matter. As keyed up as he was, Yoran

  doubtless bypassed tact without noticing. "Fine. Give me your plan."

  "I'll develop it as we go along and collect more information. For the present, hmm, I must do some figuring. I'll get back to you with the coordinates of the next observation point in about an hour." The physicist cut the connection.

  "An hour," Laurice said. "That'll serve."

  Vargen blinked. "What?"

  "An hour of our own. Let's take advantage. We may not have more for some time to come."

  Fifty hours of leap, study, leap were unendurably long and unbelievably few. At the end, the travelers met in the saloon. Word like this should be face-to-face, where hand could seize hand. For it, they gave themselves boost, weight, that they might sit around the table at ease, perhaps the last ease they would ever know.

  Yoran rose. Pride swelled his stumpy form. "I am ready to tell you what I have found," he said.

  "After the Python Confederacy." Copperhue murmured the words, but forgot to keep the 'trans equally quiet. Well, Laurice thought beneath her heart-thumping, Children's Day morning expectancy, of course all beings want their races given all due honor, whether or not they like the governments.

  Yoran surprised her with a mild answer: "True. And your people scarcely came upon this by last-minute accident. As long as they've been spacefaring, I imagine they found it hundreds of years ago. They-the rulers, that is-saw the potentialities, but bided their time till the climactic moment neared. Erthumoi couldn't have kept a secret like that. " Has his triumph made him gentler? wondered Laurice. I'm glad for you,

  Yoran.

  "What are the potentialities, then?" Vargen demanded.

  "I don't know," the physicist replied. "Neither do the Naxians, or they wouldn't be making such an effort. " He paused. Something mystical entered his speech, his whole manner. "An unprecedented event, rare if not totally unique

  in the universe. Who can say what it will unleash? Quite possibly, phenomena never suspected by us. Conceivably, laws of nature unknown even to the Forerunners."

  And what technologies, what powers might spring from those discoveries? went chill through Laurice. For good or ill, salvation or damnation. I can't blame the Naxians of the Python for wanting to keep it to themselves. I wish we humans could.

  "Tell us what it is!" she blurted.

  The three assistants shifted on their bench. They knew. Their master had laid silence on them. This was to be his moment.

  He looked at her and measured out his words. "I can give you the basic fact in a single sentence, milady. Two black holes are on a collision course." Copperhue hissed.and Vargen softly whistled.

  Black holes, Laurice evoked from memory. Suns two--or was it three?-or more times greater than Florasol, ragingly hurdnous, consuming their cores with nuclear fire until after mere millions of years they exploded as supernovae, briefly rivaling their whole galaxy; then the remnant collapsing, but not into the stability of a white dwarf or a neutron star. No, the mass was still too huge, gravitation overcame quantum repulsion, shrinkage went on and on toward zero size and infinite density. The force

  of gravity rose until light itself could not escape.... She had seen

  pictures taken from spacecraft at a distance and by probes venturing closer. The event horizon, the sphere of ultimate darkness, appeared seldom, and only when data processing succeeded. It was asteroid size, a few tens of kilometers across at most, and screened from view. For around it wheeled fire, the accretion disk, matter captured from space, spiraling

  ever faster into the maw, giving off a blaze of energy as it fell.... No

  transmissions had come from nearby. The stupendous gravity dragged at radio and light waves, reddened them, twisted their paths. Its tidal forces

  stretched a probe asunder and whirled the fragments off into the disk....

  Most of the knowledge was to Laurice little more than words-quantum tunneling, Hawking radiation, space and time interchangeably distorted....

  I'm not badly informed for a layman, she thought. I remember Professor Arbureth remarking how much is still unknown to anybody in any of the Six Races. He opined that in the nature of the case it always would be unknown too, because there is no possible way for information to reach us through the event horizon. But if a pair of them crash together-

  "That must be rare indeed," Copperhue said low.

  "Unless at galactic center?" Vargen mused.

  "Conjecture, " Yoran snorted. "Yes, perhaps lesser black holes are among the stars that the Monster engulfs, but no probe has survived to tell us what's going on there. Here the event is out where we can watch it." He

  grew milder. "Also, this is not a simple linear collision, such as we

  believe we have some theoretical understanding of. That would be vanishingly improbable, two singularities aimed straight at each other.

  This will be a grazing encounter.

  "From our observation of orbits and accelerations, we've obtained the masses of the bodies with considerable accuracy. They are approximately nine and ten Sols. That means the event horizons are about sixty kilometers

  in diameter. Calculation of closest approach-that involves some frank

  guesswork. We have good figures for the orbital elements. If these were Newtonian point masses, they'd swing by on hyperbolic paths at a distance of about thirty kilometers and a speed of about one-third light. But they

  aren't, and it'd be a waste of breath to give you exact figures, when all

  I'm sure of is that the event horizons will intersect. The ship has programs taking relativistic and quantum effects into account. I've -used them. However, certain key answers come out as essentially nonsense. The matrices blow up in a mess of infinities We simply don't know enough. We shall have to observe.'

  "Can we get that near and live?" Vargen asked.

  "As near as the Naxians, I daresay." Yoran sounded boyishly bold and

  careless.

  "How near is that, do you suppose?"

  "Probably closer than humans would venture, if this had been our project from the beginning. We'd send in sophisticated robotic ~ vessels. The Naxians will do their

  best with probes, but that best isn't very good. No nonhuman race's is. They all keep trying to copy from us, and never get it right. "

  "Every species has its special talents," Laurice interjected for shame's sake. She wondered if Copperhue cared, either way.

  "Give me a figure, will you?" Vargen snapped.

  "An estimate," Yoran replied. "It takes into account our advanced protection systems; we can fend off more than most ships. The Naxians must have some that are equally shieldable. Integrating the expected radiation over time around the event, and throwing in a reasonable safety factor, I'd undertake to keep on station at a distance of two hundred million kilometers, for two hundred fifty hours before the impact and maybe as much as thirty hours after it, depending on what the actual intensities turn out to be. That's far too deep in the gravity well for a hypedump escape, of course, but I'd call the odds acceptable."

  He spread his hands. "Granted," he went on, "the whole reason for the exercise is that nobody can predict what will happen. I make no promises. All I say is, if I were the Naxian in charge, I'd post four live crews at approximately that distance. Two on the coordinate axis through the point of contact, normal to the tangent to the orbits at that point and in their plane. Two on the axis normal to this at the same point. I'd put others elsewhere, naturally, but these four should have the best positions, if our theories correspond to any part of reality.

  "And if I were that Naxian, I'd join one of those crews. "

  Laurice leaned forward. She shivered. "When will the encounter be?" she asked.

  "If we jumped now to the vicinity," Yoran told them in carefully academic style, "we would observe it in a little more than eleven standard days. " "That soon," Vargen murmured into stillness renewed. "We barely made it, didn't we?"

  He shook himself, straightened where he sat, and clipped, "Very well. Thank you, Dr. Yoran. If you haven't already, please put your data and conclusions in proper form

  for transmission. We've got to notify headquarters. What we've learned thus far mustn't be lost with us. Besides, I'll be interested in the exact information,-the actual numbers, too." His smile was crooked. "Personally interested."

  Laurice saw doubt on Enry; Newan swallowed; Thura laughed aloud. They foreknew. It was Copperhue who said, "Thereafter, do you intend that we shall seek the event?"

  Vargen's head lifted. "What else? On Ather, they'd never outfit and scramble another ship in time. "

  "Humans won't get another chance," Yoran agreed, and I doubt the Naxians will share what they learn. "

  Laurice paid him no heed. She caught Vargen's arm. "Yes, certainly," rang from -her. "It's up to us. That's how you were bound to think, Harul. " Yoran stood where he was. He drooped, the glee drained out of him, as if somehow gravity had reached from the lightless masses yonder.

  Neutrinos passed through hyperspace, across half the breadth of the galaxy. Their modulations carried the findings made aboard Darya. Laurice wished she could talk with her father when they were done, but haste forbade. The instruments gathered information at rates hugely greater than the transmitter could send it. Conveying all they had took several irrecoverable hours. For the same reason, the expedition would send home nothing but the new data from each stop along its course henceforward-and nothing whatsoever, once it was close to the black holes, until it was outward bound again.

  Yoran spent the waiting period in the electronics shop. Laurice supposed he tinkered with something in hopes that it would ease his tension and ... unhappiness? Or did the magnificence ahead of him drive out mortal wishes? Newan monitored the reporting. Vargen studied the facts, with Thura and Enry on hand to answer questions. In the saloon, Laurice and Copperhue played round upon round of Integer until, at length, they fell into conversation. It turned to private hopes, fears, loves. You could confide to a sympathetic alien what you could not to any of your

  own species. "I look forward to your Venafer colony," Laurice said finally, sincerely.

  The summons resounded. Crew took their posts. Countdown. Jump. A light-year from their destination, they poised.

  Words reached Laurice in her globe as if from across an equal gulf. She had instantly established that no other vessel was in the neighborhood. Absurd to imagine that any would be, those few score motes strewn through the abyss. Why, for starters, consider that the light-year is a human unit, a memory of Old Earth like the standard year and day, the meter, the gram, the gee. Nobody else uses them.... Her eyes sought the predicted coordinates on the sphere. She couldn't tell whether she picked the two sparks out of the host that glittered around. Her fingers trembled a little as she set the console viewscreen to them and turned up the optics.

  The breath caught in her throat. Magnified, amplified, two comets flamed before her. From their incandescent brows strearned flattened blue-white manes, becoming manyforked tails that shaded through fierce gold to a red like newly spilled blood. Fragments rolled behind, and she imagined the turbulence within, great waves and tides through the gas, lightnings, atoms ripped into plasma, roaring down to their doom.

  And this is only how it was a year ago, she realized. The black holes were still well apart. How far did Yoran say? I forget. The span of a thousand average planetary systems? The accretion disks had just begun to interact strongly with the interstellar medium. Their bow shocks were mostly generating visible light. Later it shifted toward X rays, harder and harder.

  "Next jump," Yoran called.

  "Ah-eady?" Vargen asked.

  The reply screeched. "Chaos take you, we haven't got a second to waste! Nothing registers here that we can't account for in principle. I've programmed everything for maximum data input and processing. Make use of it, you clot-brain! "

  Hoy, that's far too strong, Yoran, thought Laurice, half dismayed. Harul has every right to put you in confinement. Are you off your beam? Now, in these last, supreme days?

  Relief washed through her when Vargen rapped, "Watch your language. The next offense, I will penalize."

  She considered ordering the ship to show her the physicist. Maybe, knowing him, she could calm him down. The sense of deliverance mounted at his grudging, "Sorry ... Captain. May we proceed?" She hadn't wanted to cope with him.

  Darya knew the planned pattern in which she was to draw nigh. "Ten," she sang. Vargen must have given her a signal, not quite trusting himself, to speak. "Nine. Eight. Seven--

  At half a light-year, the comets burned naked-eye bright. Optics showed their tails contracted, thickened, drawn into intricate strands that looped around as if seeking forward to the hungry furnaces of the comas. Enry's voice was fall of awe and puzzlement: "Sir, that looks almighty strange, doesn't it? I can't think how you'd get curvatures like that in the gas, at this stage of things."

  "Nor can 1, " Yoran admitted eagerly. Rapture had eclipsed wrath. "The

  cosmos is running an experiment like none we've ever seen before or ever will again. I'd guess that mutual attraction is-was-appreciably distorting the event horizons. That'd be bound to affect magnetic fields and charge distributions. But we need more information. I I

  Not that it would soon reveal the truth, Laurice realized. Understanding must wait upon months or years of analysis, hypothesis, tests in laboratories and observatory ships and brains, back at Ather and no doubt elsewhere, among the Six Races. The task here set before Yoran's genius was to decide what sorts of data, out of the impossibly many his team might try for, would likely bear such fruit. "The polarizing synchrometer should-"

  The conversation from the intercom went out of Laurice's reach.

  She tuned it low and made a direct connection with Copperhue in the saloon. Her yearning was for Vargen's words, since she could not have his presence. The skipper

  shouldn't be distracted, though, nor should the others be given grounds to suspect he was. Besides, she felt sorry for the Naxian, become functionless, restricted to whatever view Darya got a chance to project on a rec: screen for it-him.

  "How're you doing?" she inquired softly.

  "We fare among splendors," she heard. "Is this not worth an island?"

  "Yes, oh, yes." A thought she had not wanted to think pushed to the forefront. "Will your-will the Pythons really let us carry it home?"

  "We have considered this before, honored one. The vessels on which I served were unarmed. The Dominators have no cause to expect us. The fleet come for the climax may include a few naval units of models suitable for rescue and salvage operations, should those prove necessary; but they are probably not formidable. "

  "I know. I remember. However, it's occurred to me--it didn't before, because on Ather we don't think that way-in a number of Erthuma societies, the military would insist on having a big presence, if only for the prestige."

  "They do not think like that in the Confederacy either, honored one. There is no distinction between organizations serving the Dominance; they are simply specialized branches of the same growth. This means that commanders can act decisively, without having to consult high officials first. You see, their intelligence and emotional stability have been verified beforehand. I warned your father that I do not know what the doctrine is with respect to preserving this secret. But I doubt that orders read 'at all costs.' Additional combat vessels will scarcely be sent from afar, under any but desperate circumstances. That would mean leakage of the truth, from crewfolk not predisciplined to closeness about it. Besides, the Confederacy is as desirous of maintaining stability as any other nation is." Copperhue hesitated. "I do counsel that we avoid undue provocation. "Well, you can advise the captain. Can't you?"

  "I can try. Perhaps I shall bring you into conference, if possible. Your rapport with both him and me may enable you to make ourselves clear to one another. "

  It thrilled in her, "I can't imagine any better service. Thank you, old dear, thank you."

  Jump went the ship in a while. And again, presently, jump. And hour affei hour, jump, to a different point of view, to a new distance, but always nearer, jump, jump, jump.

  Jump.

  At one light-hour, the incandescence around the black holes made them the brightest of the stars. You could have read by that livid radiance. Their closeness was deceptive; Darya had emerged well off any normal to their paths. Yet even as Laurice watched, her unaided eyes saw them creep nearer. Chill went through her, marrow deep. Second by second, those colossal accelerations were mounting.

  And what when -they met? Yoran believed the masses would fuse. If nothing else could leave such a gravity well, how could the thing itselP. But this was no simple, head-on crash, it would be a grazing blow. He said the case had been considered theoretically, centuries ago, but not as fully as it might have been, and had since lain obscure--probably in the archives of other races too-for nobody awaited it in reality. He spoke of problems with linear and angular momentum, potential fields, quantum tunneling by photons, leptons, baryons, gravitons. The event horizons should undergo convulsive changes of shape. Still more should the static limits, below which everything from outside was ineluctably hauled into orbit in the same sense as a black hole's rotation. These twain had opposite spins with distinct orientations. What wavelike distortions might their meeting send out through the continuum? Already, space-time around each was warped. In a black hole's own frame, the collapse to singularity was swift. To a safely distant observer, it took forever; what she saw was not a completed being but an eternal becoming. Yet if somehow the inside of it should be bared, however briefly, to her universe, there was no way even to guess what would follow.

  "Emissions from spacecraft power plant detected," said Darya - "I estimate the nearest at fifteen million kilometers. "

  No surprise, here. Nevertheless Laurice knew guiltily that for a pulse beat she had let her attention stray from her guns. Vargen remained cool: "Any indications that they've noticed us?"