The brilliant London lawyer Oliver Rathbone made a big mistake - he undertook to defend a noble person brought to court for libel, and, it seems, completely deservedly. After all, his client accused not just anyone, but the famous Princess Gisela, and not just anything, but the murder of her own husband, Crown Prince Friedrich! Although all of Europe had been admiring the story of their great love for twelve years, since Frederick, because of his marriage to Gisela, renounced the crown in his homeland and went into exile... So the very thought of such a crime would seem blasphemy to the jury. Now Rathbone must either find evidence that his client is right, or say goodbye to his career. But Inspector Monk comes to the aid of his friend...