Claude, who temporarily replaces his father at the head of a department store, falls in love at first sight with a pretty female customer. He finds out that she is named Solange and that she is the goddaughter of Professor Hauteclerc, who runs a private psychiatric hospital. To come closer to the girl of his dreams, Claude has a crazy idea: he pretends to be mad so as to be placed in Hauteclerc's institution.

Un jeune commerçant qui a aperçu une délicieuse jeune fille dans son magasin apprend que celle-ci est internée dans une maison de santé. Ne pouvant l'approcher, il se fait enfermer, subit les traitements les plus durs et, finalement, réussit à attendrir l'objet de ses rêves.