Guido Renzi and his lawyer friend chase a beautiful girl to return a purse that he lost and after a long drive in the car reach the laboratory of an improvised astrophysicist - the girl's father - who, together with another scientist, is about to take off in the direction of Mars aboard a missile.

Cipriano Duval is an Italian who has emigrated to Paris, where he works in a pediatric clinic as a nurse.