Though perhaps Isaac could. If Isaac was alive, and if he understood, finally, the nature of the gift Avram Dvali had given him.

CHAPTER TWENTY-NINE

It was warm in the ruined stockroom, and although most of the dust had settled out of the air—seemed to have been absorbed, somehow, into the rubble—no fresh air flowed into the enclosed space. Sooner or later, Sulean Moi thought, and most likely sooner, that would become a problem. And there was the body of Diane Dupree to think about. If she could tolerate such thoughts.

She crawled along the accessible perimeter of the room for the second time, feeling with her hands for anything hopeful—a draft or some promisingly loose heap of rubble. And for the second time found none.

She had begun to believe she might die in this awful place on this awful planet, haunted by the ghost of Esh. Haunted, that is to say, by the Hypotheticals.

In whom she did not believe, at least not in the sense Avram Dvali believed in them. The Hypotheticals were a network of self-replicating spaceborne machines. Some long-extinct civilization must once have seeded its local environment with these devices, or perhaps it had happened more than once, a multiple genesis over many millions of years. Either way, once variable self-replication was introduced into the medium of interplanetary and interstellar space the process of evolution was engaged—different from organic evolution in every detail, but not in principle. Like organic evolution, the process had generated strange and gaudy complexities. Even such apparently "engineered" devices as the Spin barrier that surrounded the Earth, or the Arches that linked planets separated by vast distances, were ultimately no more intrinsically intelligent than such biological constructions as a coral reef or a termite hill.

The periodicity of the ashfall and the truncated grotesqueries it generated were proof enough, she thought. What had been installed in Esh—and in Isaac—was nothing more than a tragic susceptibility to alien tropisms. Esh could not be a "communicant" because there was no one with whom to communicate.

Evolution did, demonstrably, produce minds, and she supposed it was possible that the long interstellar evolution of the Hypothetical machines had also produced minds—locally, temporarily. But such minds, if they existed, were the byproduct, not the process. They controlled nothing but themselves. They couldn't be "the Hypotheticals" as Dr. Dvali imagined them to be.

She remained unnerved, however, by the obvious fact that Isaac remembered Esh, who had died many years before Isaac was born. If Esh had become a memory in the networked ecology of the Hypotheticals, could such a memory possess volition? And who or what was the rememberer?

"Sulean—"

This was Mrs. Rebka, who wouldn't leave Isaac's side. Her voice came out of the darkness of their sealed tomb as if from an infinite distance. "Yes, what?"

"Do you hear that?"

Sulean hushed her own thoughts and listened.

An intermittent scraping. The tack-tack-tack of something solid tapping stone. Followed by more tentative scraping.

"Someone's trying to dig us out," Mrs. Rebka said. "It must be Avram and the others, they must know we're here!"

Tick-scratch-tick. Yes, maybe, Sulean thought. But then Isaac said, very suddenly and with startling clarity, "No, Mrs. Rebka. It isn't the other people who want in. It isn't people at all. It's them."

Sulean turned toward the place from which Isaac's voice had come. She quelled her own fear and said, "Isaac, do you really know what's happening?"

"Yes." His tone was unexcited. "I can see them."

"The Hypotheticals?"

A pause. "You could call them that."

"Then explain it to me, please, Isaac. You're part of it now, aren't you? In a way Esh never was. Tell me what's happening."

For a moment there was only the tick-scratch-tick at the walls of the fallen building in which they were trapped.

Then Isaac began to speak.

CHAPTER THIRTY

Turk navigated by the fractured remnants of pavement and sidewalk through the alien forest that had lately been a settlement for oil riggers. He managed to find the parking lot of the workers' mall—white lines, cracked blacktop—and from there it was a short hike to the complex where they had left Diane Dupree, Sulean Moi, Mrs. Rebka, and Isaac.

Except it wasn't there anymore. He came upon rubble where the trees had grown more densely, further obscuring the dim light of what was, by now, afternoon. Here was an embankment of broken tile, wall-board, wood, sheet aluminum twisted into unlikely shapes. Beyond that, in the dimness, steel beams stood in skeletal rectangles. Some of these beams and pillars had been entwined by the rootlike extensions of the trees.

"We'll angle toward the south end of the mall," he said. Where the food store was or had been. "Might be something still standing there."

The haunted forest, Lise thought.

Boy, was it ever.

She found herself silently reciting a line from a storybook her father had read to her when she was small, book and story all forgotten except (in her father's melodramatic drawl) Into the dark forest they stepped. Into the dark forest they stepped. Into the dark forest of trees that harbored birds that resembled sheets of torn paper, the forest from which (another fragment of the same story) they must escape, but that was easier said than done. Because here there were wolves, or worse, and night was coming, and she didn't know the way out. She wanted to lunge up from under the covers and grab her father's hand. Wanted it more than anything.

But couldn't. She scolded herself, in her mother's voice this time: Don't be stupid, Elise. Straighten up. Fly right, girl.

She nearly flew right past a heap of plaster-specked metal, until Turk pointed it out: it was the car Mrs. Rebka had been driving when the two groups separated. She recognized the steel-mesh tires, on prominent display because a rod-like tree trunk had sprung up from the cracked pavement and tumbled the vehicle on its side. Useless now, the car, but any car would be useless until this forest shrank back into the ground, and that seemed unlikely to happen soon. If we leave here, Lise thought, we'll have to leave on foot. And that was a daunting prospect. The good news was that the car was empty: Isaac and the women weren't inside, hence might still be alive elsewhere.

"So we're near the food store," Turk said, and Dr. Dvali ran recklessly a few yards ahead, where the remains of the storefront were vaguely visible behind a picket of alien growths.

The quake hadn't spared this part of the mall, and if the others had taken shelter here they might be dead. This was so obvious it didn't need saying. Dr. Dvali wanted to start digging immediately—futile as that might be, the three of them versus a few tons of debris—but Turk said, "Let's circle around back first. The structure looks maybe a little more intact back that way."

Dvali stood slump-shouldered at the brink of the rubble field a moment longer, and for the first time Lise felt a degree of sympathy for him.

All night, all morning, Lise had been imagining the women and Isaac huddled in some safe place; the group would be reunited, and then she and Turk could set out for some safe harbor even if the mad Fourths insisted on staying here in Freakland. That was her best-case scenario.

Now it looked like that might not happen. The story might end tragically. There might be no way to escape from the dark forest. Maybe, she thought, for Isaac and the women, the story was already over.

The rear of the mall seemed at first glance more intact than the front, but that was only because the concrete loading bays had been left undamaged by the quake. Structurally, everything was a mess. Lise felt heartsick, and Dr. Dvali seemed to be suppressing tears.