“What’s going on?” he said.

Seria Mau examined him carefully. He looked like a plucked chicken in that light. His flesh looked as grey as his hair. She wasn’t quite sure what she had seen in him.

She said in her ship’s voice: “This is your stop, Billy Anker.”

The clone whimpered, clung on harder, shut her eyes as tight as she could. “You might well do that,” Seria Mau advised her: “It’s your stop too.” She dialled up the mathematics.

“Open the airlock,” she ordered.

She thought for a moment.

“No, wait,” she said.

Two minutes later, something levered its way out of nowhere on a remote curve of the Beach, at the edge of a system no one had ever bothered to name. Empty space convulsed. A splatter of particles organised itself in a millisecond or two from a fireworks display into the ugly lines of a K-ship—the White Cat, her torch already alight, heading in-system at a shallow angle to the ecliptic on a brutally straight line of fusion product.

Surveys of the system, carried out fifty years after humanity arrived on the Beach, had found a single solid object in a braiding orbital dance with gas giants. Though a little large, it was strictly a moon. Tidal heating in its core had raised the surface to temperatures resembling Earth’s, generating also a loose and wispy atmosphere which featured the gases that support life. Against a curious greenish arc of sky ballooned the salmon-pink bulk of the nearest gas giant. A single fractal structure occupied the entire planet. Though from a distance this resembled vegetation, it was neither alive nor dead. It was just some mad old algorithm which, vented from a passing navigational system, had run wild then run out of raw materials. The effect was of endless peacock feathers a million different sizes: a clever drawing ramped into three dimensions. Mathematics trying to save itself from death.

Plush and velvety, surrounded by a vanishingly thin mist of itself, this structure defeated the eye at all scales. It did something strange and absorbent to the light. It lay brittle and exfoliated, fragmenting into a viral dust of itself, a useless old calculation which had accidentally become an environment. There was a biome: among its quaint bracts and stalks, local life forms moved with a kind of puzzled stealth. The logic of the ecology was unclear, its terminal fauna provisional. At dawn or dusk, something between a bird and a marmoset might be seen, making its way painfully to the tip of some huge feather to stare anxiously at the face of the gas giant, before it closed its eyes and began a fluting territorial aubade. No one had stayed long enough to find out any more.