If husbanded carefully, the trillion tons of ice and hydrocarbons might keep a couple of hundred humans at a time—along with their plants and animals—alive for a hundred generations or so.

Just enough time. For in a couple of thousand years, the comet’s hurtling velocity would ebb as it approached its new aphelion, out where the Hot was only the brightest star. And out there, drifting slowly, were hundreds of billions of other great lumps of primordial matter left over from the birth of the solar system. Once their present near-hyperbolic velocity had leaked away to mere meters per second, there ought to be plenty of chances to snag other comet heads.

Saul stopped at a point where the guardrail hedge opened at the rim of the curving wheel. He was still thinking about the images Virginia had shown him, just a few minutes ago, in the little glade beneath her tea house… a simulation of those days, so long from now, when the men and mechs of Halley would nudge their tired, depleted old home near fresh new ice-specks in the great blackness. Perhaps they would seize two, three, or more, and drift apart again on their new colonies.

And from there? Virginia’s simulation projected no limits. The Oort Cloud was vast, and humans were noted settlers.

And our own sun’s Oort Cloud brushes against the comet shoals of other stars…

The image she had presented was daunting. She already contemplates in terms of aeons… it’s going to take me a lot longer to get used to thinking that way. My own style of immortality is different. It retains the feel of Time as no friend.

He passed Lani Nguyen-Osborn, sitting on a park bench under a dwarf maple, nursing her new son. Her eldest child—little Angel Angelique—played in the grass nearby.

Lani smiled and waved. Saul grinned. They had spoken only an hour ago when he was on his way to see Virginia. He was due to have dinner with Carl’s family later tonight. In the meantime, he still had work to do.

The vista of an Earthy city cleared as his section of the wheel approached ground level. He stepped through the break in the guard hedge into the microgravity of Halley’s caverns, and let himself drift into the soft sand braking embankment. A cloud of particles puffed outward as he landed, then slowly settled to the floor.

He launched off toward the exit leading to his laboratory. The half-living sphincter lock cycled him through to the tunnels with a soft, moist sigh.

The gene-pool survey had been very good news—even if it had reminded him that neither he nor Virginia would ever contribute. All of his clones were sterile, and her physical body had long ago become part of the ecosphere.

Perhaps it was for the best, at that. For his clones would be round as the generations came and went. The decedents of Carl and Lani and Jeffers and Marguerite would be mixing their genes, sorting and restoring until a new species of humanity emerged. If all of those “Saul Lintz” models also kept having children, over the centuries, it would muck up the process.

Heaven forbid! He laughed at the thought. He had long ago come to terms with the irony of his situation…the clever design of his blessing and his curse.

Now, though, another bit of research occupied him. Something even more significant. More amazing.

Down at the end of one little-used corridor, Saul spoke a code phrase in Aramaic and a door hissed open. He slipped past the gene-crafted guard-cockatrice into his private lab. He had his neural tap socketed into place before his frame even settled horizontally onto the webbing.

Program… Rock of Ages… hecommanded his personal computer. Colors shimmered and steadied.

The image on the central holo tank was of that deep, secret room down at the heart of the Weirder domain, where Suleiman Ould-Harrad had met his faith, in his own way. The horned, carved-stone bier rotated in the holographic image.

To the right, another display showed a sample taken from that ancient rock—symmetrical fossil ribs tracing the outlines of a creature of a very ancient sea.

More screens rippled with data, with microscopic closeups, with detailed isotopic profiles.

For a year now. Saul had been in touch again with Earthside specialists. With Halley confirmed to be on a near-hyperbolic trajectory, the hysteria had dampened on Earth. Guilt and shame played on what passed for news channels, these days. Some of the gifts the colonists had beamed back had also deepened the feeling that contact should be maintained until the planets merged with the roiling noise of the sun and all talk between brethren ended in the hiss of static.

The Earth scientists had worked on his data, confirming in detail what he had already worked out in general.

Nearly five billion years ago—in one of the gassy, dust-rich spiral arms that laced the Milky Way like filmy pinwheel spokes—a young, massive, hot star had raged through its short life and exploded in the titanic outburst of a supernova. In so doing, it had seeded nearby space with glowing clouds of heavy elements, from carbon and oxygen to plutonium and osmium… all cooked up while the blue giant had coursed through its brief but glorious youth. Save hydrogen and helium, all the elements that made up the planets—and human beings—had originated in that way, from great outbursts of primeval heat and light.

This supernova not only spewed great gouts of heavy matter into space. It also drove mammoth shock waves, which compressed the interstellar gas and dust, forming eddies and whirling concentrations.

A Jeans Collapse—named for a great twentieth-century astronomer—was triggered. Here and there amid the shocked, metal-enriched clouds, whirlpools condensed, flattened, formed glowing centers…suns.

And round those new stars, tiny fragments coalesced, from rocky bodies nearer in, to great gas worlds, to distant, vast swarms of tiny lumps of frozen vapor…

All geochemistry had, until now, been dated from the supernova that triggered the formation of the solar system. Never had any matter originating outside that event come into human hands. Until now, that is.

The rock Suleiman Ould-Harrad had found under the heart of Halley had none of the isotopic ratios scientists were familiar with. It came from a completely different episode of creation.

Joao Quiverian would have loved this, Saul thought. He mourned the loss of a good mind to the madness of those long, hopeless years.

And Otis Sergeov, as well. I do hope we’ve learned a lesson.

The final data unfolded before him, the confirmation of several years’ guesswork and labor.

Proved. The stone came from ocean sediments laid down long before Earth had begun to swirl and form out of cosmic debris. The little animals whose fossils he had traced had swum in seas of a world not very unlike the Earth, with chemistry not so very different. But they had lived before the sun was even a star to wink in their cloud-flecked skies.

Saul read snatches from the message from Earth.

Radiation damage to constituent crystals indicates close proximity to the explosion. Not more than a quarter of a lightyear away from a supernova.

He picked up a chunk of the stone, wearing smooth now from being handled. The planet that this had come from must have circled a smaller star that had the misfortune to be near the giant when it exploded, blowing it to bits and scattering its pieces into the smoke rings of the spiral arms.

Were there watchers, that night? he wondered. Might intelligence have looked up, knowing what was coming, making frantic plans, or resigned peace?

The odds were against it. Probably the planet had only animals and vegetation, and the end came swiftly, without anticipation. That did not make the event any less awesome, or less biblically terrible.