Dominique is a pretty, vivacious girl. When she witnesses a car theft, she throws herself and her bicycle under the vehicle. Jacques Mareuil, whom she then blackmails, pays her a sum to cover her debts. In reality, Mareuil, a policeman, is keeping an eye on Atcheminov, the owner of the car, but, wanting to prove that he is an unscrupulous trafficker, he comes up against Dominique's impetuosity time and again. It all ends up like in a good comedy.

Raymond Rouleau
as Jacques Mareuil

Jean Lefebvre
as Le trombone

Sophie Desmarets
as Dominique Laugier

Jany Vallières
as La comtesse

Mario David
as Tonio

Magali Vendeuil
as Henriette (as Magali de Vendeuil de la Comédie Française)

Grégoire Aslan
as Atcheminocc

André Versini
as François de Chambon

Jacques Varennes
as Le Président

Mona Dol
as La concierge