Pierre Trévoux is a preppy smug young man who lives with his household in a desirable mansion.He always prides himself on his courage ,and he boasts he can be a hero if by any chance he could live a true adventure .His self-importance and his vanity get on his friends 'nerves,and they decide to teach him a lesson .They plan a hoax and simulate a burglary in his house,and pretty Arlette's kidnapping.Unfortunately,true gangsters intervene ..