Earth is adrift. Its mass is spent, the moon ditched, and the sun is not even a memory. Five thousand humans live in its last city, Thule. None know where they started or where they are going, least of all Lowell.

Lowell scrubs the pipes beneath Thule. He knows where to push silt and how to break down a beluga carcass. For everything else he listens to Renth. Renth is a foot taller than anyone else in Thule and yet has never fallen in the reservoir, never been locked in a smoker. She knows the pipes matter. She listens to Lowell, and Lowell talks to no one else. He doesn’t need Thule, only Renth, height and all, until she pushes him down the deepest hole in the pipes.

To return to Thule he will brave incineration, muskoxen, the vacuum of space and a giant fan. He seeks Renth, her embrace or her death, and to deliver a message he does not understand.