Six months after his devastating loss, Balthazar has disappeared from Paris without word to his friends. Anchoring his sailboat near an isolated community Balthazar discovers a badly burned corpse. When a furious Capitaine Bach arrives to investigate they stumble into something horrifying.
Bach is certain they've caught Lise's killer; Balthazar is unconvinced. Then they are called to the body of a woman beaten to death and left in a church. Balthazar realises the victim has been participating in mixed martial arts fighting.
Two bodies are found in a disused tunnel. They have been shot, coins left on their eyes and a circle of salt drawn around them. One of the couple is a medium which leads Balthazar into a world he cannot fathom.
The body of a middle aged woman is found in her home, throat slashed, and her 12-year old son is missing. Bach discovers the boy is linked to the brutal murder of a family 2 years ago. Meanwhile, Balthazar's life takes some surprising turns.
A deranged clown is filming himself at the scene of several murders. Balthazar's relationship with Maya is moving forward fast, but Helen makes an error that has serious consequences.