On the plain beyond the cube, scattered over a couple of kilometers, were a half dozen objects of similar size and different but equally simple shapes—huge cylinders, octagons, truncated spheres, conical sections. Some were sandstone-colored, like the cube; others were black, cobalt blue, obsidian black, cadmium yellow. Any one of them could have enclosed a small city, and all of them were creeping at the same patient speed toward the distant mountains and the sea. “So immense,” Oscar said breathlessly, “these objects, but such an insignificant fraction of the whole body of the Hypotheticals.” The stark light cut shadows into his mask and made him look like a timid animal peering out of a hole. “It would be easy to commit the impertinence of fear.”

Way too easy, out here on the polar desert of the planet that had given birth to the first human beings and had become an unmarked grave for billions more. While the scientific crew activated sensors and surveying devices, I walked without Oscar’s permission (but he scurried after me) to within a few hundred yards of the base of the cube.

It was old. It wasn’t weathered or cracked, and for all I knew it might have been manufactured a day or an hour ago, but it felt old—age seemed to radiate from it like cold air from an icefield. Inches ahead of it the thin layer of new-fallen snow was disappearing from the desert floor, sublimating into the night air.

“The Hypotheticals are endlessly patient, Mr. Findley. They’re older than most of the stars in the sky. To be so close to their work … this is a sacred moment.”

We all wore earpieces to facilitate communication. I had turned down the volume on mine—the few simple Voxish words I had learned weren’t much use here—but we both heard a burst of excited chatter erupt from the technical crew. Two beams of high-intensity light swept upward.

The beams diffused into what appeared to be a pale cloud at the top of the cube. Snow or mist, I thought; but no—elsewhere, the sky was clear. The cloud appeared to be boiling off the top of the cube itself—and the other, more distant objects were generating similar clouds, pale mists that sifted down gently despite a wind that should have dispersed them.

I took an instinctive step backward. Then: “Look,” Oscar said in a hushed voice.

Something had landed on the arm of his protective suit. Oscar regarded it with a kind of terrified reverence. A snowflake, I thought at first. But on closer inspection it was more like a tiny crystalline butterfly—two pale and perfectly translucent wings beating over a body the size of a grain of rice.