Sherlock Holmes is dead. Or so it is assumed. The world knows the great detective went over the falls a Reichenbach with his nemesis Professor Moriarity. But as Holmes’ body was never retrieved, a number of frauds, fakes, and charlatans have come forward since to lay claim to his identity, and it falls to Dr Watson to disprove them. Then a telegram arrives informing Watson that three men, each claiming to be Holmes, have been committed to a remote asylum off the coast of Scotland. Now Watson must discover if one of the mad men is the real Sherlock Holmes.