Devastated by Pierre's death, Josephine struggles to keep herself together. Laure is also affected, and the two women find some common ground in their shared grief. The police investigation into the double murder has uncovered a link between Sandrine Jaulin and Zacharie Gabbai's criminal gang. An operation is launched to catch Zach and his accomplice. Roban refuses to step down from the Jaulin case in the aftermath of Pierre's death, and resolves instead to bring in a promising young colleague, Carole Mendy.

Gilou is taken into custody, as his team looks on in dismay. Herville clashes with his superiors. The identity of Lucie Jaulin's biological father is finally established. Egged on by Edelman, Joséphine defends Tarek Ziani and engages in a power struggle with Roban. The police go ahead with their plan to catch Zacharie Gabbai, but the operation is a risky one - especially now that Gilou is out of action.