Six weeks ago, the angels of the apocalypse descended to destroy the modern world. Now seventeen-year-old Penryn helplessly watches as an angel fly away with her kid sister. Determined to get her back, Penryn makes a pact with a rogue warrior angel, Raffe, who has lost his wings and his honor. Tentatively they form an alliance and head to San Francisco, the angels' stronghold, to get Penryn's sister back.