If any one man is responsible for the rejuvenation of the postwar Swiss film industry, that man was director Leopold Lindtberg. Matto Regiert (Madness Rules) was co-adapted for the screen by Lindtberg from a novel by Friedrich Glauser. Heinrich Gretler stars as Police Constable Studer, the hero of several of Glauser's most popular works. This time, Studer must solve the murder of the director of an insane asylum -- and it's not (surprise, surprise) the most likely suspect, manic-depressive patient Herbert Caplaun. For box-office purposes, Matto Regiert stresses a romantic subplot involving Caplaun and nurse Irma Wasem.

A policeman is not convinced that the prime suspect in a murder case is realty guilty and so decides to reinvestigate the case, despite the lack of co-operation from locals.