Beatrix von Falklenburg, the childless wife of an impoverished and, it must be said, neglectful, Count, was living the life of a Prague socialite when a murder involving her elderly uncle pulled her into the orbit of Edward VII of England and the German Kaiser. And into that of a Prague police inspector, as well as into a deeper interaction with her unflappable butler, Müller, and her lady's maid, Sabine. All of which is recounted in The Countess of Prague.

Her role in that 1904 investigation has brought her to the attention of the Hapsburg Emperor Franz Josef I, who has her summoned to his palace in Vienna. There he tasks her with probing the "murder/suicide" in 1889 at Crown Prince Rudolf's hunting lodge at Mayerling and looking for possible papers that might contain revealing information or evidence of what happened there. Did Rudolf murder Baroness Marie Vetsera and shoot himself? And might there remain something that would reveal "the dreaded secret" that could topple the Hapsburg dynasty, as rumor had long hinted? Something that has survived to 1905?

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. Thus she becomes involved in what proves to be the murder of the Great Orsini, Master Illusionist, and in what follows. It's an investigation she cannot drop, despite her mission for her Emperor.