The unscrupulous bar owner Otto Grolbek hires the masseur Janos Klewe to murder his landlady. He then wants to inherit her and get his hands on some urgently needed money. But things turn out differently than planned: Janos is killed during the attempted murder in Portugal and Vera returns to Germany terrified. Now Otto has to commit the crime himself and kills his landlady. He disguises the crime perfectly, but has not reckoned with Inspector Mungowski's subtlety ...