Her role in an investigation detailed in The Countess of Prague, has brought Beatrix von Falklenburg to the attention of the Hapsburg Emperor Franz Josef I, who has her summoned to his palace in Vienna to investigate the murder/suicide of Baroness Marie Vetsera and Crown Prince Rudolf. But before Trixie is handed her assignment, a terrible murder occurs on a snowy Prague funicular railway. Inspector Schneider pulls her away from a night at the opera to the crime scene. The only clue to the identity of the decapitated corpse is a tiny slip of paper in his waistcoat pocket - a piece of paper with Trixie's telephone number on it.