C'est pas moi.. .c'est l'autre

Small time thief Vincent Papineau is pursued by the Mafia, from whom he stole a desk that he believed to be of little value, without knowing it contained $250,000. While trying to escape, he's stopped by two police officers who mistake him for Claude, a fellow policeman on holiday following the death of his partner. Vincent decides to benefit from their mistake by moving in to his double's home, thus throwing off the gangsters. But he also has to become a police officer and partner up with Lucie, Claude's young colleague who's intrigued by his new behavior.