The story of 38-year-old Gabriel Chevalier, a former member of the criminal investigation department. He is unemployed and marginal with a daughter to look after, when a previous informer offers him the job of carrying a briefcase whose contents he ignores in exchange for a fabulous fee. His employers, whose identity he ignores, assure him that the briefcase contains nothing illegal. Gabriel, who thinks the money will solve all his problems, accepts the terms of the contract: to never, under any circumstances, open the briefcase. His deliveries takes him to strange destinations to meet even stranger clients. Gabriel fast becomes rich, finally emerging from years of misery. But as he starts to take himself back in hand, his conscience and policeman's instinct are reawakened…