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.

Balthazar and Bach investigate the death of a young waiter from a casino.

Balthazar and Bach are found with a dying man in the trunk of the car they are using to escape a military base.

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.

Javier has escaped and Balthazar is devastated and furious. Bach's reservations about Maya remain, sending Delgado and Balthazar into grave danger.