Désiré Le Sec has just won the "amateur policeman contest" and he is so glad he 's telling all the people around.He is an insure agent ,and his boss,his uncle,is annoyed :a man took out a big life insurance and died soon afterward.

A sporty and chivalrous young man creates, with some comrades, a society whose goal is to protect honest people against rogues. He finds himself thrown into unforeseen adventures, at the end of which he will discover love.