A famous singer disappears in a plane crash. Her two little girls are given a new home by their grandfather. Unfortunately the good man has an old housekeeper who goes out of her way to make their lives impossible. In desperation the two brats run away to Paris. Meanwhile, the girl's father manages to steal important documents. In the end, Gaby and Ginette track down their mother who had not got killed at all. All is well that ends well.

Story is primarily based on the adventures of Antoine, a young telegraph messenger on his second night of work. He is given three telegrams, one of which is for the president of the Camber of Deputies. Excited, Antoine runs his bicycle into a truck and loses the telegrams. What follows is an amusing and agonizing search for the missing messages. He is assisted first by a glum, wise-beyond-her-years little girl, Amelie; an off-duty police superintendent, a schoolmaster, a cookie-tin maker and a fireman. The harmonica musical theme is played by Flore Falvey.

A journalist who deals with the column "courier du cœur" has the absurd idea of ​​launching an investigation into the death of a pianist whom he claims to have been murdered. To dazzle his wife, a reporter for the newspaper, he disguises the facts in such a way that the police suspect him, then declare him guilty. It takes a number of adventures to get him out of this mess and get him back into his section.

A trio of criminals gradually become entangled in theft and crime. Serge is arrested, his mistress, Hélène, and his accomplice, Michel, both become lovers, try to exonerate him and use false fingerprints first, then after Serge's conviction, gloves covered with the same fingerprints of the prisoner.

Kohlman, the attorney for the Fournil bank, diverts money from the institution. To hide his malpractices, he imagines to remove the director, the young and overconfident Clement Fournil, during a cruise at sea on the yacht Emile Frechisse.

Henri, a basically honest fellow, accepts to work for a gang of burglars only to revenge himself on Fournier-Salville, a wealthy businessman who once ruined him. His role will be to become Fournier-Saville's majordomo and at the same time to inform the burglars so as to facilitate their work. But once in the house he performs his task so well and so stylishly that he becomes indispensable. Moreover, Eve, the businessman's capricious daughter, does not remain insensible to his charms.

Suspected of murder, a man disappears under mysterious conditions, which only increases the charges against him.