Promo for the Third Episode of Sherlock Series 3

BBC One has released the following promo for the third episode of “Sherlock” Series 3, which will air on Sunday, January 12th. Titled “His Last Vow,” the episode is described as follows:

A case of stolen letters leads Sherlock Holmes into a long conflict with Charles Augustus Magnussen, the Napoleon of blackmail, and the one man he truly hates. But how do you tackle a foe who knows the personal weakness of every person of importance in the Western world?

BBC One has also debuted this behind-the-scenes clip featuring the cast and crew talking about Sherlock’s best man speech, how things will change for Sherlock and John, and Martin Freeman and Amanda Abbington on working together.