Moriarty: Clockwork Empire (Moriarty: Clockwork Empire #3)

In a London opium den, a monster is killed by the police with seven bullets to the body. At the Diogenes club, an investigator and his partner thwart the Machiavellian plans of a card-playing automaton, and that evening the monster's alter ego will come out of the hospital unscathed... and Holmes and Watson are on the case!