I had first met Turk in the Equatorian desert, before he or I had passed through the temporal Arch. Out of ignorance or spite, and not quite by accident, Turk had once killed a man, and he had built a life on the foundation of that guilt. His best acts were acts of atonement. His failures he accepted as a kind of punishment. He craved a forgiveness he could never earn, and he was horrified when the Coryphaeus offered him that forgiveness. Accepting it would have dishonored the man Turk had killed (who was named Orrin Mather); and the people of Vox, by submerging all such feelings in their closed limbic collectivity, had made themselves monstrous in Turk’s eyes.

Allison was a different case. She was a native of Vox whose artificial persona had allowed her a rare glimpse beyond the boundaries and limitations of her life. By adopting that persona as her own, she had successfully liberated herself from the Coryphaeus. The liberation had come at the expense of her family, her friends, and her faith.

It was a bargain I understood very well.

I wanted these two people to survive. That was why I abetted their escape. Even then, I had doubted they could successfully cross the failing Arch. But I made it possible for them to live a little longer, depending on how you measure time.

*   *   *

For more than a millennium the Hypothetical machines had been scouring the surface of the Earth, dismantling and interpreting and remembering the ruins of the civilization we had built on the planet that gave us birth.

There was no conscious will behind this act of scavenging, no thought, no agency. It was simply behavior that had evolved over time, like photosynthesis. The devices Turk had confronted on the Antarctic plain had accumulated a rich storehouse of data. Earth’s tangible resources—rare elements that had been refined by human activity and concentrated in the wreckage of our cities—had already been extracted and transferred to orbit and beyond, where the space-faring elements of the Hypothetical ecology had feasted on them. The Hypotheticals were very nearly finished with the Earth.

But their sensors (orbital arrays of devices no bigger than grains of dust, complexly networked) had detected Vox as soon as it crossed the Arch and directed ground-based scavengers toward it. What the Voxish prophecies had imagined as an apotheosis was just a mopping-up exercise: the last berry plucked from a barren, dying bush.

The Hypotheticals arrived not long after Turk and Allison had fled, as a cloud of insect-sized disassemblers. They were sharp-toothed and efficient. They exuded complex catalysts that unzipped chemical bonds; they came through the melting walls like smoke, followed by the toxic external atmosphere. Gusts of poison blew down the corridors and walkways of Vox Core. This was a mercy, in a way—most of the citizens succumbed to asphyxiation before they could be devoured alive.

Could I have saved them?