The mathematics hid them nicely. It even found a sun, small, G-type, a bit tired, but with a row of planets that gleamed in the distance like portholes in the night.

What was memorable about the system, which was called Perkins’ Rent, was the train of alien vehicles that hung nose to tail in a long cometary orbit which at aphelion was halfway to the next star. They were between a kilometre and thirty kilometres long, with hulls as tough and thick as rinds, coloured a kind of lustreless grey, shaped as randomly as asteroids—potato shapes, dumb-bell shapes, off-centre shapes with holes in them—and every one under two feet of the sifted-down dust blown out of some predictable and not very recent stellar catastrophe. The dust of life, though there was no life here. Whoever they belonged to abandoned them before proteins appeared on Earth. Their vast nautiloid internal spaces were as clean and empty as if nothing had ever lived there. Every so often part of the train fell into the sun, or ploughed ship by ship into the methane seas of the system’s gas giant: but once it had been perfect.

The ghost train was the economic mainstay of Perkins’ Rent. They mined those ships like any other kind of resource. Nobody knew what they did, or how they got here, or how to work them; so they cut them up and melted them down, and sold them via a subcontractor to some corporate in the Core. It made a local economy. It was the simple, straight-line thing to do. The used-up ones were surrounded by unpredictably shifting clouds of scrap: cinders, meaningless internal structures made of metals no one wanted or even understood, waste product from the automatic smelters. The White Cat found a snug place in one of these clouds, where the smallest individual unit was two or three times her size. She gave herself up to the chaotic attractor, shut down her engines and was instantly lost: a statistic. Seria Mau Genlicher woke up in a fury from her latest dream, opened a line to the supercargo.

“This is where you get off,” she told them.

She dumped their equipment from the hold and then opened the human quarters to the vacuum. The air made a thick whistling noise as it blew out. Soon the K-ship had a little cloud of its own, comprised of frozen gases, luggage, and bits of clothing. Among this floated five bodies, blue, decompressed. Two of them had been fucking and were still joined together. The clone was the hardest to get rid of. She clung on to the furniture, screaming, then clamped her mouth shut. The air roared past her, but she wouldn’t give up and be evacuated. After a minute, Seria Mau felt sorry for her. She closed the hatches. She brought the human quarters back up to pressure.