For many years M. Hire has lived a recluse's existence in a seedy Paris lodging house. He has no friends, receives no letters, goes out only to his office or to the cinema. One evening, a brutal killing occurs nearby. A young girl is murdered and her handbag is snatched. When Hire's landlady -- a shrill busybody and gossip - sees a towel in Hire's room, covered with blood from a shaving cut, she jumps to the wrong conclusion and suspects him of the murder. And when she recalls that very late during the night of the crime, she had to pull the cord by her bed to let someone into the house, she is doubly convinced of Hire's guilt. Hardly able to suppress her excitement and self-importance she informs the police of her suspicions. Based on George Simenon's short novel Les Fiançailles de M. Hire