Due to Benedict Cumberbatch and Martin Freeman's increasingly busy schedules, it's becoming much more difficult to lock down the actors for more seasons of Sherlock. After the close of the third season it became clear that they wouldn't be able to jump right back in due to the actor's schedules, so the idea of a special one-off episode set in Victorian London began to take shape. The special, titled The Abominable Bride, is set to air on January 1, 2016, but according to Benedict Cumberbatch, more specials could be a possibility if both Martin Freeman and himself continue to be as busy as they've been.
I think if it becomes impossible to schedule a season every year – or year-and-a-half – then yeah, absolutely, why not [do more specials]? It's a great deal of fun, this [new episode], but it does advance things. It's not just on it's own.
I've said before that I hope Steven Moffat and Mark Gatiss go this route, a special every other year would be a welcome treat for Sherlock fans as well as give Benedict Cumberbatch and Martin Freeman more time to pursue their other projects. A fourth season of Sherlock is set to start shooting next spring and despite both actors moving on to much bigger things, both Cumberbatch and Freeman are determined to stick with the series. Benedict Cumberbatch spoke with Digital Spy to say:
I'm still enjoying it – and we'll see how the next series goes, but I've said many times before I'd love to keep aging with him. As actors, what intrigues us all to come back and play these characters is that there is scope for them to expand and change and evolve. It'd be an interesting experiment. Martin [Freeman] and I started this relatively young compared to a lot of pairings of Holmes and Watson, so why not?
Series co-creator Mark Gatiss joked that "whole civilizations have risen and fallen between seasons of Sherlock, we've accidentally cast the two biggest stars in the country and it is quite tough [to schedule]. We're not deliberately trying to ruin people's lives. It's just very difficult!" Sherlock: The Abominable Bride will air on January 1st, 2016, but will also be screened theatrically on select screens on January 6th and 7th.