The trip back to Central, under Uber escort, was almost anticlimactic, skim-running along velvety, moss-lined halls and passing the checkpoints of various clans with elaborate but apparently routine ritual.

Even to Saul it was obvious that they were taking a long way back, dropping deep into the comet to move northward before beginning to climb back up again. “Why are we going so far out of the way?” he asked when they had descended to tunnels he had never seen before—twisty paths following soft veins of primordial snow.

Sergeov shrugged. “Quiverian.”

Saul stopped. “Joao? I’d heard he was awake now, as well. But why are you avoiding him?”

The first Uber, the Percell named Stew, spat down a nearby shaft. “He’s th’ darkest Arcist. Th’ ape we hate.”

Saul shook his head, looking at Sergeov. “Explain please, Otis.”

The Uber leader smiled. “The old race had some superior individuals—like you and Simon Percell. Quiverian, too. He leads most rabidly anti-Percell band of Orthos, these days. Those who understand that, they are dinosaurs, and so want to stamp out us new mammals.”

Saul thought he understood. The term Arcist, once denoting equatorial environmentalism on Earth, had evolved and shifted here on Halley. Now it meant the most radical Ortho human faction, as Uber stood for those Percells who believed there could be no compromise with unmodified human beings.

There was clearly intense hatred and rivalry, and yet it was also obviously under control. All factions were clearly too weak, much too dependent on one another, to wage open war.

“I’m puzzled, Otis,” he said as they resumed their journey. Down here the tunnels seemed to have been hewn by hand, rough and winding, following paths of least resistance through the rocky ice. “If you feel that way, why aren’t you having children, like some of the Ortho bands?”

One of Sergeov’s men snarled angrily, and Saul realized he had brought up a taboo topic. Sergeov cut back the blue-faced fellow with a sharp word. He turned back to Saul.

“We have a few. Came out better than Orthos’ pitiful little wretches. One, we hope, can maybe someday learn to read and write.” His face was briefly contorted in painful recollection. “We do not experiment anymore. What is point, when everyone is doomed anyway, eh? Those Orthos in Quadrant Nine, they are immoral to bring babes up just to suffer, to die.”

So, Saul thought. They do know the truth.

“That’s why the level of violence is so low, even though you hate each other so much,” he ventured.

Sergeov nodded. “Everybody will die together, anyway. But we need workers to keep things going as long as possible. Nobody wants to go by cold, by starvation.”

“Nobody ’cept maybe Ould-Harrad,” one of the others ventured.

“Ould-Harrad!” Saul blinked. “Then he’s.”

“Become a wild-eyed mystic,” Sergeov explained. “How you think a Percell like Osborn ever became an officer? Not for his pretty looks and Ortho-loving ways, I tell you!”

The other two Ubers laughed. “No. Ould-Harrad started talking to God. Resigned his commission. Lunatic is tool of Quiverian, now. Spiritual leader of the Arcists,” he said sarcastically.

Saul could believe the last. It was a wonder the stark silence of the long watches had not driven more of them farther toward the fringe of human experience.

Sergeov shrugged. “Let us go now. I take you back to Central. I must talk to Osborn anyway. Clear up some stupid accusations of that crybaby Malcolm.”

Saul did nut move, though. He was staring, blinking, down a cross tunnel toward a phantom light that wavered to the distance.

The others turned and saw it too. One Uber hissed, “Clape. It’s th’ Ol’ Man himself!”

Saul drifted toward the shape, curious. Then he saw that there were two, no, three of the ghostly figures, moving along the walls like great spiders, picking through the wall growth.

A hand gripped his arm and pulled.

“We go now,” Sergeov grunted.

“What are they?” Saul asked in wonder. For a moment he thrilled to the thought that they might be an as-yet-unknown form of Halley-Life—huge and highly structured creatures.

“Now, Saul Lintz. Those can be dangerous.”

Saul blinked again, and realized that the slowly approaching creatures were shaped as men, but their outlines were fuzzy, fringed, as it were, with a cloudy, milky edge of shimmering fronds.

“Ingersoll?” he wondered aloud.

“Old Man of the Caves,” Sergeov agreed. “And some of other mad ones who joined him. Come now, Lintz, or we leave you.”

Saul nodded and began backing away with them. There would be time to study mysteries. Patience would pay off better, in the end, than impetuous curiosity.

Anyway, his palms were sweaty and his mouth drier—as he watched the ghostlike shapes grazing through the Halleyform forest—than they had been during the fight with Sergeov’s Uber warriors. Saul hurried along with his escorts, promising himself that he would be back when he knew better the rules of this strange place and time.

The halls near Central—still fibercloth-lined, still scoured at intervals with ultraviolet and microwaves and kept clean by a few mechs that had survived the decades—seemed like an oasis not just from another century but from a different world.

“My business is with Osborn,” Sergeov told Saul. “Take my advice, Lintz. Be careful which faction you join, after recuperation. A few Ortho groups are not vicious baboons.”

Saul had heard Sergeov’s radical Percells described in pretty nasty terms, as well. Where there was tribalism, he had long decided, there was no way to avoid criminality.

“Some groups accept both Percells and Orthos.” he told Sergeov. “It’ll have to be one of those, if we join any faction at all.”

“We…” The legless Uber leader thought. “Ah, you and the Herbert woman.”

“Another Ortho lover— “one of the others began, but a sharp look from Sergeov shut him up.

“There is one last thing,” Saul said as the Percells were turning to go. He reached into his belt pouch and pulled out a silvery tool.

“I want some blood and tissue samples for my new medical inventory, if you fellows don’t mind. The Survivors and the Plateau Three bands have already contributed, and I’m sure you’ll be; happy to cooperate.”

The Uber with the bad teeth snarled and reached for his knife. But one more time the Russian cut him off. Sergeov’s eyes seemed to glitter as he presented his arm to Saul. And a silent message seemed to say that he would expect a favor of his own, someday.

If I had not once worked with Simon Percell, Saul thought as he took samples from the other two, would Otis have even saved my life this afternoon?

On the Ubers’ chests the Sigil stood out starkly, red against blue, a tribute to a man long dead at his own hand, who might have seen some of what was to come, but could never have imagined how far it would all go.

He visited for some time with Virginia in her recuperation unit, checking her progress carefully and reassuring her that the slot pallor was fading nicely. He kissed her and gave her a mild sedative for her insomnia. Then Saul went down to his lab.

The samples from the Ubers went through the same preliminary analysis as he had performed on his other subjects. The first results seemed to be just the same.

Oh, there were different accumulations of microfauna in their blood and sputum. The Percells’ immune systems seemed slightly less damaged, not as overstressed as the colony’s remaining Ortho complement. That was no surprise. The expedition had started out less than one-quarter Percell. Now the ratio among those healthy enough to be awake was even or better in favor of the genetic augments.