One of the world's foremost spots for astronomical observation, the Atacama Desert in Chile is also where, in October 1973, 26 people were executed by Pinochet's Caravan of Death. Decades on, a petition gathers for a constellation's stars to be dedicated to them. Nona Fernández is made a godmother to Mario Argelles Toro, star HD89353, and asked to write a message to his family. When her own mother begins to suffer from fainting spells, she accompanies her to neurological examinations. There, the mapping of her mother's brain activity calls to mind the night sky, as memories light up into a complex stellar tapestry. Weaving together the narrative of her mother's illness with stories of the cosmos and of her country, she braids astronomy and astrology, neuroscience and memory, family history and national history into an intensely imagined autobiographical work.