The Paris police are desperate to bust drug kingpin Roger Massina. To do it, they want pimp Dede Laffont to serve as their inside man (known as la balance in French). Dede refuses: Informants never live very long. But Detective Palouzi isn't taking no for an answer. Sure enough, the police put pressure on Nicole Danet, the prostitute who's also Dede's girlfriend, forcing him to make a decision that could rob him of everything.