Eccentric research chemist Arthur Biddle isn't a safe man to be around: he's caused two plants to burn down and done extensive damage to another, managed to break a few traffic regulations, wrecked a policeman's motorcycle and has accidentally broken the arm of police chief Sinclair—who also happens to be his fiancee's father.

Hannah King has two reasons for being in Rome: to win back her husband, who's courting an Arabian princess; and to land a role in Italian director Aldo Carmenelli's new art film.