London 1901. The city is in the grip of "monkey man mania". Intrepid explorer Drake Patterson has caused a media storm following his astonishing discovery of a frozen ancient man in the remote Himalayan Mountains. This primal man has been triumphantly transported back to England as proof of the missing link in evolutionary theory. The upcoming auction of the specimen causes a stir amongst academics and the board of the British Museum.

Colonel Sapt of the Ruritanian Court journeys to England on a secret mission to save the country from anarchy. His mission is to engage the services of Rudolf Rassendyll once more to impersonate the King while the monarch recovers from a serious illness. But Rassendyll has mysteriously disappeared. In desperation, Sapt consults Sherlock Holmes who, with his faithful companion Watson, travels to the Kingdom of Ruritania in an effort to thwart the plans of the scheming Rupert of Hentzau in his bid for the throne. 

December 1889. Fresh from debunking a 'ghostly' hound in Dartmoor, Sherlock Holmes has returned to London, only to find himself the target of a deadly vendetta. A beautiful client arrives with a tale of ghosts, kidnapping and dynamite on a whisky estate in Scotland, but brother Mycroft trumps all with an urgent assignment in the South of France. On the fabled Riviera, Holmes and Watson encounter treachery, explosions, rival French detective Jean Vidocq...and a terrible discovery.

Sherlock Holmes is an unparalleled genius. Warlock Holmes is an idiot. A font of arcane power, certainly. But he's brilliantly dim. Frankly, he couldn't deduce his way out of a paper bag. The only thing he has really got going for him are the might of 1,000 demons and his stalwart companion. Thankfully, Dr. Watson is always there to aid him through the treacherous shoals of Victorian propriety and save him from a gruesome death every now and again.

Maid and occasional cook Mary Fellowes has been accused of attempting to poison her employers and the evidence against her is damning - or is it? Is she the scheming and vengeful woman that others describe? Or is she innocent, caught in a web of deceit? Holmes and Watson must follow the evidence, exposing long-buried family secrets and hidden conflict, in order to discover the truth and prevent a deadly injustice.