Balthazar

On Balthazar’s flight back to Paris, several passengers have convulsions after being poisoned, and the killer is on board. Can Balthazar ensure a safe landing?

While Balthazar is fending off questions from his psychologist, who wants him to open up about his traumas, he's called in on a case. A human foot has been found by a dog in a Parisian suburb. After recovering the victim's entire body, Camille is notified that a second victim has just been reported—but his head is chopped off. Who's behind these savage attacks on seemingly unrelated victims?

When a little girl is abducted from her room in the middle of the night, Balthazar and Camille must act quickly to try to save her life.

Due to Balthazar"s antics, a colleague is assigned to assess him: coldhearted Olivia Vésinet. He's thus overjoyed to be called to a crime scene, if only to get away from her. Three teenagers have been beaten to death in a car scrapyard, and the main suspect is a man whose house the kids robbed. But why would the man slaughter them for stealing trinkets—unless the trinkets held a dreadful secret?

While delivering a lecture at the medical school, Balthazar is taken hostage by a student who claims his father was wrongly accused of killing his mother.

When documentary filmmakers arrive to report on the Forensic Institute in Paris, the mood there turns positively chilly. Eddy and Fatim are no longer speaking, Camille hates being filmed, Delgado hams it up, and Vésinet and Balthazar are openly at war. While everyone settles scores, a man"s skeleton is discovered, whose disappearance echoes the vanishing of another man, exactly one year earlier.

Vésinet sends Balthazar to investigate illegally killed cows in the village where he grew up, and to which he never wanted to return. Luckily, Camille tags along to help.

Charged with double homicide, Balthazar has no choice but to become a fugitive to find out what is happening to him and who is persecuting him.