Léon, a humble civil servant, has the unusual ability to walk through walls, however thick they are. One day, he falls madly in love with a charming hotel thief by the name of Suzan.

Bourvil
as Léon Dutilleul

Joan Greenwood
as Susan

Gérard Oury
as Maurice

Henri Crémieux
as Mr. Lécuyer

Roger Tréville
as Félix Burdin

Jacques Erwin
as Gaston

Frédéric O'Brady
as The Medical Specialist

René Worms
as An Employee at the Ministry

Nina Myral
as Mrs. Eloise

André Dalibert
as