Taking advantage of their uncle's absence, André and Raymond Rafet organize a New Year's Eve party at his house. The uncle returns unexpectedly, disturbs the party, threatens his nephews to disinherit them and then locks himself in his office. A few minutes later, he is found dead, poisoned.
Chénérol, a wealthy merchant, one day discovers that his wife is having an affair and that his nephew is playing with him. Indeed, the latter, Théodore, does not work but earns money by using a few dirty tricks.
