At the end of “Sherlock” Season 3, Sherlock Holmes (Benedict Cumberbatch) was heading into exile until the apparent return of James Moriarty (Andrew Scott) gave Sherlock a chance to remain in London.
For several months, “Sherlock” co-creators Steven Moffat and Mark Gatiss have teased a “Sherlock” Christmas special that would be filmed before the fourth season. Today, BBC released the first photo from the upcoming Christmas special with Cumberbatch and his co-star, Martin Freeman as Sherlock Holmes and John Watson, respectively.
While “Sherlock” is very firmly set in the modern day, both Sherlock and John are wearing Victorian style clothing from the original era of Sherlock Holmes stories as created by Sir Arthur Conan Doyle.
Because “Sherlock” is a relatively grounded series, I think we can rule out the time travel theories. The most likely explanation is that Sherlock and John don the period clothing at some point during the special.
But there is a fun theory that the “Sherlock” Christmas special will stand completely apart from the regular series and take place in the Victorian era with Cumberbatch and Freeman playing the characters in their original setting for the first time.
At this point, the “Sherlock” creative team isn’t adding any context to the photo. It’s just meant as a teaser for the eventual reveal.
The bad news is that the “Sherlock” Christmas Special will likely be held back for Christmas 2015, unless BBC decides to run it out of the holiday season.