Episode List: Sherlock (2010)

"The special is called the Abominable Bride," announced Gatiss, adding that it is based on 'Ricoletti of the club foot and his abominable wife', which is one of the cases Watson refers to in the original Sherlock Holmes stories but not one that Sir Arthur Conan Doyle actually wrote.

Sherlock waits to see where Moriarty will make his posthumous move. One mysterious case in particular baffles Scotland Yard - but Sherlock is more interested in a seemingly-trivial detail. Why is someone destroying images of the late Prime Minister Margaret Thatcher? Is there a madman on the loose? Or is there a much darker purpose at work? Something with its roots deep in Mary Watson's past? (imdb)

Sherlock faces perhaps the most chilling enemy of his long career: the powerful and seemingly unassailable Culverton Smith - a man with a very dark secret indeed. (BBC)

A dark secret in the Holmes family rears its head with a vengeance, putting Sherlock and friends through a series of sick, manipulative psychological and potentially fatal games