Twice I had to stop and brush Oscar free of the butterflies. I was too terrified to wonder why I was apparently immune to them. Oscar clearly wasn’t: his protective clothing was ragged now, torn in places by their small but razor-sharp legs, and some of those ragged patches were speckled with blood. I worried about his mask and oxygen supply and I tried to make sure I cleared the most vulnerable parts first. For a while we ran arm-in-arm, which seemed to keep the swarms at bay. All the panicked chatter and terrified screaming that had filled my earpiece slowly began to fade, and the final silence, when it came, was even more terrifying than the screams. I couldn’t say how long or how far we ran. We ran until we couldn’t run any more, until there was no sound but the roar of my own labored breath. Then I felt a sudden resistance, Oscar’s arm tugging me backward, and I thought, They got him, he’s dead weight—

But he wasn’t. When I turned to face him I found his suit was clean: there were no butterflies on him. His face through the moist blur of his mask was shocked but relatively calm. “Stop,” he gasped. “We’re out of range. We’re beyond the perimeter now. Please, stop.”

I took a long look back.

We had come a fair distance. The abandoned lamps were still working, the Hypothetical machines plainly visible in a skewed crosshatching of artificial light. Nothing human was moving.

The wind blew grains of snow around our feet and the stars glittered overhead. We stood shivering, waiting for whatever might come out of the darkness after us—another attack, a straggling survivor. But there was no one, nothing.

Then, in quick succession, the distant lamps began to blink off.

*   *   *

We reached the aircraft guided by signal-finders built into our suits. It was a long walk but we were too shaken to talk much. Oscar eventually managed to establish voice contact with Vox Core, and he exchanged curt messages with managers and military personnel. Remote telemetry had broadcast most of what happened, and Vox was already attempting to analyze the data. “Probably,” he said at one point, “our presence triggered a defensive reflex of some kind.” Maybe so. But I wasn’t Voxish and I didn’t have to believe in the benevolence of the Hypotheticals—I didn’t have to make excuses for a senseless slaughter.

Our aircraft rested on the Antarctic plain like some incongruous deposition from a vanished glacier. I asked Oscar whether he would be able to pilot it back to Vox.

“Yes. Really, I just need to tell it to carry us home.”

“You sure? You’re bleeding, Oscar.”

He glanced down at his ravaged clothing. “Not badly,” he said.