I liked the unique setting of this novella, a planet which was pulled out of its orbit by the Aurals (its original inhabitants), and is now so far from its sun that the atmosphere is frozen solid. Humans were invited to the planet several hundred years ago by the Aurals, but have not managed to make contact with them and are reduced to living in a cave system and melting the frozen air to breathe. The sublimation angels of the title are the puffs of air that are released when the mirror ash surface is scraped off, exposing the frozen surface, and the Low Kids believe that they are the souls of the dead.

The social structure of the stranded humans and the presence among them of AIs in human bodies were also interesting, but I didn't really get into the story until the revolt of the Low Kids against the Moms, in the last third of the story when it really picked up pace. ( )

Sublimation angels are puffs of evaporating air from a freezing alien planet that, for generations, a human colony has been struggling to survive on, sent out of its orbit into space by the Aurals, inscrutable aliens in the form of balls of light, that the expedition was sent to contact. The story follows the adventures of Chicka, whose brother Omare becomes a human 'angel', seemingly reconstituted after being recycled for not following orders. Very different from the author's previous stories here. ( )