Professor James Moriarty, prominent scientist, keen analytical mind, and a dabbler in less than savoury doings, is somewhat surprised when an unknown caller is shot by a crossbow bolt on his doorstep. Meanwhile the Professor's one-time associates, the journalist Benjamin Barnett and his wife, the former Cecily Perrine, are having their own troubles on the Continent. Things turn deadly when they find themselves in the midst of an attempted assassination of a German prince, and in Vienna, the younger son of a British nobleman—indulging in "The Great Game" of amateur spying—finds himself framed for the murder of his paramour and the assassination of an Austrian Duke. While a lesser man might be daunted, Moriarty is merely intrigued. With the unwanted help of his often nemesis Sherlock Holmes, Moriarty must connect the many threads of the mystery. But he is facing his most cunning opponent to date, and this is no game...