The young captain Lemoine has been killed during an intervention he made without the agreement of his superior, the Major Mallory. The latter is inconsolable. Lemoine was like a spiritual son, he even asked him to be the godfather of his seven-years-old son. After this tragic event, Mallory has now only one goal: to find Lemoine's killers. He makes it his business. However, he will have to compromise with and to oppose the young Captain Lindberg sent from Paris to supervise the investigation.