A gang of formidable criminals is operating in the affluent neighborhoods of Paris and its suburbs. Investigators will attempt to catch them in the act.

The BRI men are facing an extremely rare situation. A madman armed with a grenade is holed up in the heart of Paris and they'll have to bring him to heel. Meanwhile, the police are hunting a French drug trafficker on the run. They'll be following the fugitive's trail for several weeks.

The BRI sets up a surveillance system to intercept drug traffickers in the act. They also need to intervene in a hostage situation.

The Paris BRI is interested in a Renault Mégane RS that was stolen and hidden in an underground parking lot. This car brand, highly prized by criminals, is likely going to be used to pull off a major heist. But the vehicle disappears before being placed under surveillance. The following night, in the Paris suburbs, an ATM explodes.