After a girl is kidnapped and then recovered, she refuses to reveal the identity of her captor.

The Investigation Unit searches for a suspect in the kidnapping of Romane and Audrey.

An incarcerated murderer wishes to apologise to the families of his 12 victims before dying.

Patrick Lacenaire continues his efforts to obtain his pardon.

The body of Vicky, a teenage girl, is fished out of the river.

In an abandoned house, five corpses are found by a woman who is searching for her daughter.

The Investigations Unit perseveres to find Adèle and unravel the mystery.

The Unit mobilises to apprehend the killer before the list of his victims grows longer.

The serial killer is still on the run and the Unit discovers his involvement on a forum.