Days after the encounter at the Reichenbach Falls, Pinkerton detective agent Frederick Chase arrives in Europe from New York. Professor Moriarty’s death has left an immediate, poisonous vacuum in the criminal underworld, and there is no shortage of candidates to take his place --- including one particularly fiendish criminal mastermind. Chase and Scotland Yard Inspector Athelney Jones must pursue this sinister figure, a man much feared but seldom seen, who is determined to stake his claim as Moriarty’s successor.