Queen Isabella, wife to Edward II of England, has been dispatched to France in an attempt to bring about peace between the two countries, and Sir Baldwin de Furnshill must accompany her with his friend Simon Puttock. But the day after their arrival, a servant is found murdered, with Baldwin's dagger lying next to the body.
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.