The squad must identify a murdered male torso found in the 20th arrondissement. Laure Berthaud, fearing the loss of her premature baby, has returned early from maternity leave, but in her absence the team has changed. She must reclaim her rightful place and deal with the new commissioner, Arnaud Beckriche, who has given the team a week to get results.
The victim has been identified as a young police officer named Mercier who worked under Commissioner Herville, former boss of the 2nd DPJ. The team is more committed than ever to solving the case. Lawyer Josephine agrees to collaborate with Eric Edelman and pushes her client to plead guilty. Judge Roban probes a male prostitute’s suspicious death.
The Camara brothers are interrogated in custody. Joséphine wakes up, half naked, next to the port of Arsenal and even if she does not remember anything, understands that she was drugged with GHB and raped. She confides in Laure who encourages her to file a complaint. She refuses and, in a psychologically weakened state, she goes to defend her client, Thomas Veber. Meanwhile, Roban suspects prosecutor Machard to be involved in one of his cases.
Laure gets the lowdown on Gilou’s investigation of the Camaras. At Joséphine’s request, the police go to Thomas Veber’s old home to search for the hammer that will incriminate him. A doctor believes that Judge Roban’s state of health is incompatible with his duties. Laure and Gilou go to see someone in connection with the Camaras.
The body of a teenager is found on the site of Cléry squat. Laure and her team are dispatched to the scene, it is being investigated by SDPJ 93, who keep them at bay. War is declared between Joséphine and Edelman, who are now very much on opposing sides. Laure continues to investigate Joséphine’s rape. Judge Roban seeks help from Machard on the Camara case.
Why did Mercier get involved with the proceedings of young Justine? This is the question that taunts Laure and her team. They return to the high school to interview the victim’s classmates. Vern seeks help from Joséphine regarding a case of unfair dismissal. Joséphine does everything she can to get her rape complaint dismissed, but Laure doesn’t understand this about face.
Even if she refuses to file a complaint, Josephine doesn’t intend to let her rapist go unpunished. Beckriche finally tackles the Mercier affair head on. He mobilises his entire team to monitor two possibly corrupt cops from the Cléry BAC. Laure and her colleagues continue, in parallel, to look for Justine’s classmate, Maria. Herville learns from the mayor of Cléry that one of his men warned of the search at the Roma camp.
The Camara brothers are back in the sights of Berthaud’s team. Now associated with Edelman’s office, Josephine is interested in the case that Roban was preparing to file. Roban is slumped against a wall. Several clues lead Laure and her men to a Chinese business that might link corruption at the BAC to the Camara brothers.
Tensions mount in La Cité des fleurs after the death of the young Camara. Calvi worries about his mother who lives there, and puts pressure on Jolers to calm things down. Beckriche and Herville are summoned by the Préfet who wants to stop the situation from escalating. At the hideout, the Berthaud team are ordered to return to the station. Drissa Camara calls Jolers and Calvi to account.
Roban was more uncompromising than usual in the Bodin case, and it backfires when Josephine compels him to publicly answer for his actions. Meanwhile, Machard also cites him in looking for a loophole. The Berthaud team think they have picked up Maria’s trail. Drissa makes the mayor of Cléry sing for her.
Fromentin is troubled by the degree of complicity between Laure and Gilou. Feeling excluded, he sees it as a betrayal, given that he let his wife and children walk out on him so he could devote himself to the team. The noose tightens on Gilou while Laure tries to cover for him. Josephine is struggling to recover from her disappointment at Roban’s appearance in court.
The corrupt officers are in custody, implicated up to their necks in the Mercier case, but a procedural error could jeopardise everything. The Berthaud team question a doctor, struck off the register, who may have given birth to the young Justine. And finally, Laure is reunited with her baby who can finally leave the hospital.