She is the perfect assassin. A Russian orphan, saved from the death penalty for the brutal revenge she took on her gangster father's killers. Ruthlessly trained. Given a new life. New names, new faces - whichever fits. Her paymasters call themselves The Twelve. But she knows nothing of them. Konstantin is the man who saved her, and the one she answers to. She is Villanelle. Without conscience. Without guilt.
Criminal investigating officer Hanne Wilhelmsen considers the possibility of a serial killer as she tracks down a series of numbers written in blood appearing on walls all over Oslo.