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.

Micheline, who fled to Paris with the man she is in love with, finds herself on her own when he abandons her. She lands in a reformatory from which she manages to escape.