A trainee spy. A washed-up operative. A doomsday cult with a city to burn. Xiu thinks her recovery mission is leading her to the middle of nowhere, but when she reaches a derelict city on the Chinese border, she finds a seasoned operative with only a pistol, twenty rounds and a broken heart. Cut off from the rest of the world, Xiu and her new, begrudging mentor face an unimaginable enemy: a paramilitary apocalypse cult with room for two, and irradiation for two million.