While Gilou awaits his trial in prison, Laure's group is being sidelined. They do their utmost to be given one case in particular: that of the murder of an unaccompanied Moroccan minor in Paris's Barbès district.

Laure and Ali suspect Souleymane, a young migrant who was close to the victim and whom Josephine decides to defend.

The team is conducting its investigation in Barbès, where unaccompanied Moroccan minors are being exploited by receivers of stolen goods.

Laure flouts the ban on seeing Gilou, who gets himself hired as a bouncer in Cisco's nightclub. There, he meets the security manager - Cisco's son, Titi

Josephine agrees to defend the mule in exchange for the release of Souleymane, who's being held by a cocaine dealer known as "l'Alsacien".

Laure and Ali identify "l'Alsacien" and get to work on a tracking device that was hidden under his car by members of a rival gang.

Gilou is instrumental in helping Cisco's gang acquire some weapons. Laure, who was staking him out, confronts him. Josephine is moved by Edelman's defence of Lola, who is emancipated for good.

Laure informs Ali that Gilou has infiltrated Cisco's gang. To protect him, they'll need to play for time in their investigation - but the judge orders Titi's arrest to collect his DNA, and the operation goes badly wrong.

Just as Joséphine returns to Paris with Youssouf, Souleymane disappears. Judge Vargas, who was in charge of Gilou's infiltration, decides to cut his losses.

On the day of the hold-up, a last-minute change causes chaos. Laure does all she can to save Gilou, even asking for help from Edelman.