Maybe it's because Martin Freeman talked openly about the future of Sherlock very recently and spilled the beans about plans for a special episode that will release next Christmas, but for whatever reason the BBC One has finally decided to properly confirm that both a fourth season of the show and a one-off special are in the works - with production expected to get underway sometime next year (e.g. whenever the show's very busy creative forces and in-demand cast leads make room in their packed work schedules).
As was previously indicated by Sherlock co-creator Steven Moffat, Sherlock Holmes (Benedict Cumberbatch) and John Watson (Freeman) will indeed properly continue their adventures some two years after season 3 was released. The one-off special will arrive first, though, before the fourth season (which, in keeping with tradition, will be three 90-minute episodes) picks up the tantalizing story threads left dangling at the conclusion of the season 3 finale, "His Last Vow" (read our review).
Moffat, no surprise, kept his mouth shut about what to expect from Sherlock season 4, merely teasing that "we're reasonably confident that the very next thing to happen to Sherlock and John, is the very last thing you'd expect," with his comment in the official BBC press release. Likewise, Sherlock co-creator Mark Gatiss (who also plays Mycroft on the show) provided little more than an intriguing, though vague tease with his official statement:
"Series Four! At last! It's always special to return to Sherlock but this time it's even more special as we're doing... a Special! Not only THAT, we'll then be shooting three more episodes which will take Sherlock and John Watson into deeper and darker water than ever before. The whole Sherlock team are terrifically excited to return for four new adventures. The Game is on - again!"
Thus far in its run, every episode of Sherlock has drawn inspiration from an original Sherlock Holmes story or novel written by Sir Arthur Conan Doyle - modernizing the world/characters envisioned by Doyle and taking liberties with the original text, as Moffat and Gatiss and their fellow Sherlock writer Steve Thompson (who's also worked alongside the duo on Doctor Who) see fit to do. However, the series has - as Freeman recently noted - to some degree followed the "trajectory" of Doyle's literature up until now - could that change with season 4?
Probably not, though it will be interesting to see which of Doyle's Holmes stories form the backbone for Sherlock season 4; there's plenty of additional, as-yet untapped source material for the writers to draw from, after all. Likewise, it'll be interesting to see if Moffat and Co. decide to try and make the one-off special something, well, truly special - maybe a brand-new adventure, with Sherlock and John on the case?
The Sherlock one-off special will film in early 2015, possibly even January; production on season 4 will commence sometime in the months thereafter.
Source: BBC One