A German scientist murders his fiancée during World War II when he learns that she has been selling the results of his secret research to the enemy.

Peter Lorre
as Dr. Karl Rothe, alias Dr. Karl Neumeister

Karl John
as Hösch, alias Nowak

Helmuth Rudolph
as Colonel Winkler

Johanna Hofer
as Mrs. Hermann

Renate Mannhardt
as Inge Hermann

Eva Ingeborg Scholz
as Ursula Weber

Peter Ahrweiler
as Oberstleutnant Marquardt

Gisela Trowe
as Prostitute

Richard Münch
as 1. Kriminalbeamter

Lotte Rausch
as Woman on the train