A doctor who cannot figure out what is wrong with his patient refers him to a detective, whom he hopes will be able to discern the cause of his mysterious illness.
Max Landa
as Detective Landa
Reinhold Schünzel
as Freiherr von Mohrungen
Conrad Veidt
as Wilmos, sanatorium director
Hilde Woerner
as Siegnis, maid
Marga von Kierska
as Frau von Riberac
