Little Champion is raised by his grandmother, Madame Souza, to become a great cyclist.
But one day, years later, Champion while participating in the famous Tour de France, is abducted by two mysterious men in black.
The grandmother and the faithful dog named Bruno go looking for him, in a journey taking them to Belleville, where they meet the “triplettes”, eccentric stars of “music-hall” of the thirties, that decide to help them.