Working with the BIS PP group, Saïd's group prepares to intervene as the robbers board the cargo ship. Socrate and Ferracci, meanwhile, are hot on the trail of Vingre.

Helpless, the group follows a lead that Saïd had discovered before his disappearance. But the robbers are still one step ahead, and set a trap for the BRI. Vingre discovers that Inès has given information to the BRI.

Saïd is back. Battered but bruised, he resumes the investigation. The group is getting closer and closer to the robbers: the BRI discovers that a huge shipment of drugs is due to arrive in Le Havre. They know that the robbers will also be there.

Informed by Inès, the BRI tails a drug convoy led by Nina Perez. The truck is attacked by robbers who start shooting. Faced with a highly trained team, the BRI finds itself in serious trouble.

The gang of drug dealer robbers who kidnapped Mangouste contacts his wife Sadia and demands a ransom. The BRI activates its kidnapping protocol, but Sadia doesn't tell them everything.

Saïd takes over as chief of the BRI Versailles, an elite unit specialising in organised crime. Leading officers Badri, Julien, Vanessa and Socrate, he will not only have to prove his mettle but also excel at succeeding the former chief, Patrick.

The team find the identity of the second shooter; Éric Perez reveals to Saïd that he knows the people who got Sélim murdered; Saïd and Julien are following a suspect when they come across Socrate about to intercept traffickers.

After Sélim's murder, the team deal with the criminal gang to find the shooters; during Patrick's wife's funeral, Saïd uncovers the true nature of the bond that unites him and Éric Perez.

After the operation fails, Saïd is demoted, and Patrick takes over as chief of the squad again; Éric Perez is convinced that the El Hassani gang is responsible for the attack on his son and prepares for retaliation.

Socrate admits to Julien and Saïd that he was recruited to investigate several high-ranking narcotics officers suspected of covering up cocaine traffickers; Jordan, Éric Perez's eldest son, escapes an assassination attempt.