Behind it, a few moments later, came something large and lumbering. It used the sun for background cover, superimposing itself on a vibrant-blue solar flare that had sprouted only an hour before from a large magnetic arch.

She caught it with a laser burst, feeling a chill run through her mind. She would never have caught the slight, giveaway ripple of ultraviolet that betrayed the incoming warhead… except that she was monitoring the flare, as part of their ongoing research program. Jeffers had been right when he insisted on retaining the dedicated science diagnostics; it paid to keep learning.

The third was fast, closing at a hundred kilometers a second, still boosting with a light-ion drive. Virginia wondered why they had left the electrostatic accelerator on, since it made the projectile much more visible. She fired at it with the newly resurrected launchers, and in the two-second delay waited confidently for a kill signature.

None came. Her phased-array net told her why. The thing was maneuvering sideways, dodging the slugs of iron. Evidently it could pick up the microwave hum of the launchers and see the pellets as they came.

She immediately fired all her harnessed laser banks.

They, too, missed. By then only four seconds remained and she did not even have time to sound alarms in the tunnels of Halley.

Desperate, she drove the power level of the of the gigahertz net up a terawatt and shifted the system from RECEIVE to TRANSMIT. The array had never been used this way. For a brief instant it could have sent a hail to a civilization across the galaxy itself, if anyone along the beam happened to be looking. The spider-web dishes could probe and pinpoint. Virginia fired a pulse of electromagnetic energy at the precise dot that swam in her triangulated worldview.

They had safe-armed this warhead. As the electromagnetic tornado burst upon it, the chip-mind aboard fired the compressing explosives before they could evaporate. The equivalent of twenty megatons of blistering fusion energy flowered in the black sky above Halley, raising a flash-burn of ivory fog from the weathered ice.

Throughout the battle Virginia had alerted no one. The men and women and families went on about their lives, untroubled. Only when workers on the surface wondered about the sudden flare of brilliance did she call Carl and deliver the news that their great battle had come and gone in the time it took Carl to put down his cup of coffee.

“Any signs of others?” Carl asked tensely.

“None;” Virginia said. “I have extended my search to a light-hour all around us, and find nothing.”

Lani came coasting into Central, her face drawn and pale. “I heard your announcement, Virginia. How close did they get?”

“As the Duke of Wellington said after Waterloo…” Virginia’s voice shifted to a heavy, aristocratic British accent, “‘It was a damned near thing.’”

“And they’ll try again, if we continue on our planned trajectory;” Carl said soberly. “They won’t tolerate us using the Jupiter encounter to loop us into the inner solar system. They’ve got years to shoot at us, remember. When we come back inward, they’ll strike again. That attack may fail, too. And the next one. But eventually…”

“Those murderers! Lani cried. “We were willing to accept quarantine, but that wasn’t enough for them! Just to protect themselves from any chance of exposure to Halleyforms, they’d kill us all.”

Carl felt the inevitability of what he had to say, the end of so many hopes. “Time to face facts. We can’t come back in from the cold.”

Lani frowned. “But that means…”

“Right. We’ve got to choose a trajectory that’ll take us outward after Jupiter. It’s the only way to stay out of Earth’s reach.”

Virginia asked, “You think that will be enough to make Earth stop?”

Carl shook his head. “We’ll have to hope so. We’ll chart a course that takes us far into the outer solar system.”

Lani looked at him, biting her lip, silent.

“Somehow,” Virginia said slowly, “I don’t believe they will be content with anything less than a departure orbit.”

Lani’s eyes widened. “What? Leave the solar system entirely?”

“Effectively.” Virginia said sympathetically, “They will then be convinced that Halleyforms will never reach Earth.”

Carl nodded. “No point to chasing us. Too expensive, anyway.”

“What’ll we do out there?” Lani asked incredulously.

“We’ll live. We’ll die.” Carl stared, unseeing, at the main screen where numbers rippled. “Into the Oort Cloud…” he said distantly. “There are supposed to be trillions of iceworlds there, asteroid-sized. That’s what Halley was, before some nudge, maybe from a passing star, tumbled it into the inner system.”

Lani asked doubtfully, “And once we’re there? Can we use those for resources?”

He shrugged. “Maybe. We’ll have hundreds of years to think about it on the way out.”

Lani settled into a webbing, her face composed. “We’ll all be dead before then, even with sleep slotting.”

Carl felt an odd, distant resignation. Somehow he had known that he would never leave this place. They were consigning not only themselves, but all further Halley generations as well, to an outer darkness of limitless unknowns. Fleeing into the abyss.

Lani said, “I suppose we must… plan for what we can do, not what we’d rather do.”

Life’s a series of overcoming dooms, one at a time, Carl thought. He knew they could do it, too, if they simply refused to give in to despair. If we have something to live for.

Half of Stormfield Park had been turned into a nursery. The old centrifugal wheel had been reinforced to spin faster, providing a full tenth of an Earth gravity to help young bones grow strong. That was hard on some of the older generation, but still they came often, when off work, to listen to the high, piping voices shrieking in play and laughter.

Saul felt that way as he walked carefully along the grass-lined, curving path at the rim of the wheel-park, where holograms gave the illusion of a cityscape just beyond a low hedge, with skies spotted with warm, moist clouds. Mothers and nursery workers tended their growing crowd of boisterous charges nearby, watching their games, admiring the infants’ clear-eyed, long-limbed beauty.

The children had saved Halley Colony… if in no other way than by lightening the spirits of those who now knew they would never see Earth, Mars, the asteroids, or any unfamiliar human face ever again.

We are the first starship, Saul had come to realize, two orthree centuries ahead of schedule.

Oh, Halley was still tied to old Sol’s apron strings, but their ship home was irreversibly on course toward the outer cloud now, where trillions of iceballs drifted in the not-so-entirely-empty range between the stars. Alien ground. They would live or die on their ingenuity, and on whatever they had taken with them.

On that subject Saul had just completed an important study, an inventory of the genetic pool available for the coming generations. The question was an important one, for it might mean the difference between the colony’s survival or a long, slow decline into degeneracy and death.

There’s plenty, enough heterozyqosity, he had decided A broad cross section of the types that populate old Earth. It should provide enough variety. Especially with the mutation rate we can expect. The bigger problem will be maintaining a large enough population.

Halley had enough resources, for now, to keep the colony going into the indefinite future. Deuterium mined from the ice would fire the fusion piles—now relocated out on the surface to minimize waste heat—until they managed the skill to put together a proton-power generator from one of the Phobos designs. Their skill at recycling and ecological management was already impressive, and would grow.