The BBC's flagship international mega-hits Doctor Who and Sherlock are, you may have noticed, both overseen by the same man: namely Steven Moffat. His partner in crime on Sherlock is Mark Gatiss, also a regular Doctor Who writer (and occasional performer{
"My instinct," he says, "and this is probably from years of doing Doctor Who, is I’m just such a tart. If people want it, we should give it to them. But I got persuaded by Mark, Benedict, [executive producer Sue Vertue] and Martin saying, 'Look, it will never be as good as they think it’s going to be'. Then I say, 'Yes, but we’ll just bang it out and make it as good.' 'Yeah, but you can’t give everybody everything they want all the time.' I’m in the camp of giving them everything they want. But I think they’re sane and right and I’m just a tart."
Right then. Let's think about this for a minute. Sherlock Holmes showing up in Doctor Who would work. The show's anywhere-in-time-and-space format obviously lends itself to just about anything. The Doctor met Robin Hood last season, and Holmes isn't without precedent. The Doctor himself donned a deerstalker and got a bit Holmesian in the Tom Baker serial The Talons Of Weng-Chiang. And there's a rather good novel by Andy Lane called All-Consuming Fire, which mashes up Sylvester McCoy's Doctor, Holmes and the Cthulhu mythos (the Doctor also met Arthur Conan Doyle in John Peel's novel Evolution, so, y'know, you choose yer own canon).
But. The Doctor showing up in the specific modern Holmes milieu of the Sherlock TV series would, we're going to say, not work at all. It means that the London that Holmes and Watson live in is the same London that Rose, Donna and Clara live in: the London that keeps having to bat off alien invasions, often at Christmas. Holmes, it's established to Watson's incredulity in one of the original stories, doesn't know that the Earth travels around the sun, rather than vice-versa. The information is of no use to him, but it seems improbable that he's turned a similar blind eye to the Cybermen and the Sycorax and the Starship Titanic and whatever else. Where the hell was he when all that shit was happening?
However. This business of the one-off Sherlock special to be shown sometime around next Christmas possibly provides an interesting way around those problems. We don't yet know quite what's going on here, but it seems that Sherlock's next episode is set in more traditional Holmesian Victorian times and is unconnected to the wider series. If this is really some sort of self-contained, What-If, Elseworlds version of Sherlock, who's to say (no pun intended; well actually...) that, sometime in the future, there couldn't be another one with a crowd-pleasing novelty agenda...
Cards on the table: we think it's unlikely. It's the stuff of lovingly-crafted fan videos rather than primetime TV. Or maybe, at most, twenty minutes for Comic Relief or Children In Need. But give us your thoughts in the comments and on the social medias, why don't you.
Peter Capaldi's second season as the Doctor is filming as we speak. Sherlock, as we said, is back in unfamiliar form and for one night only sometime around Christmas and New Year.