At the SRPJ in Lyon, the reserved Captain Victor Farthouat and the fiery Commander Myriam Kerrouche—who cannot stand each other—form the region's most effective duo. While investigating the suspicious death of a young dentist, Victor and Myriam discover that their children are a couple. Although initially stunned, they resolve to keep their private and professional lives strictly separate and, above all, not to let personal feelings spill over into their work. But the fragile balance underpinning their partnership is about to be disrupted...