The BBC One hit starring Benedict Cumberbatch and Martin Freeman will begin shooting the special in January 2015, with new episodes shooting later next year.
Sherlock is back — in bits and pieces.
The hit BBC One series, which stars Benedict Cumberbatch and Martin Freeman and airs stateside on PBS Masterpiece, will return for a special, followed by a fourth series of three new episodes.
Shooting on the Sherlock one-off special will begin in January 2015, with the series shooting later next year, the network announced on Wednesday via Twitter.
The announcement was initially teased on Tuesday (U.S. time) with cryptic tweets from the network's handle, including a GIF of the final scene of season three, which hinted at the return of none other than Sherlock's nemesis, Jim Moriarty (Andrew Scott).
Additionally, the @BBCOne Twitter profile page was taken over by Moriarty, as featured in the avatar and the username: "Sherlock - #221back."
The news of a special comes just days after Freeman admitted to The Telegraph, "If that’s going to be a special — I’m speaking off-message here; if this was New Labour I’d get fired — I think that might be for next Christmas. A Christmas special. That’s what I understand." Yet while Watson's wife, Mary (Amanda Abbington) is also set to return, Freeman continued, “While we play fast and loose with the original stories, we generally follow the trajectory of what [Sir Arthur] Conan Doyle did. So he [Watson] gets married, and then Mary dies — so at some point presumably she'll die."
Freeman previously let the notion of a special slip in another interview in April, telling Alan Carr of Chatty Man, "Mark Gatiss may beat me up, but there is an idea for this one-off special that’s such a good idea, and as I was listening to it, I thought ‘We’ve just got to do this.’ And I don’t know when we are going to be able to do it, unfortunately. It’s a fantastic, really mouth-watering idea. But I really don’t know when we are going to get to do it."
Co-creator Steven Moffat, who also serves as showrunner for sci-fi evergreen Doctor Who, and Gatiss previously confirmed that a fourth series is on its way. "It will continue until Benedict gets too famous," Moffat said at a TCA panel in January, half-joking, with Cumberbatch adding, "I'm going to keep going with it. ... It's a schedule-providing thing. ... I love it. I find it very invigorating."
And when asked at a panel in March if they see the show continuing long into the future, Gatiss said, "The idea of growing older with it would be great. But it is hard to get everyone back together, because they have become extremely famous — except for us," to which the audience laughed.