Harry Dickson's skills were instrumental in getting blood-thirsty killer 'the Red-Eyed Vampire' arrested. The detective is invited to the small German town where the murderer was from to witness his execution. However, he cannot help but wonder whether somebody else was controlling the 'Vampire' before abandoning him. When an attempt is made to break into the condemned man's cell the night before his death, Dickson knows that the investigation is not over yet.