Synopsis: A young man named Peter Maugram appears at the front door of Sherlock Holmes and Dr Watson's Baker Street lodgings. Maugram's uncle is dead and his will has disappeared, leaving the man afraid that he will be left penniless. Holmes agrees to take the case and he and Watson dig deep into the murky past of this complex family. Meanwhile Inspector Charles Bainbridge is trying to solve the case of the "iron men", mechanical steam-powered giants carrying out daring jewellery robberies. But how do you stop a machine that feels no pain and needs no rest? He too may soon need to call upon the expertise of Sherlock Holmes.