While British viewers (and Yanks who figured out some sneaky way to watch online) have already sampled the joys of "The Empty Hearse," the Season 3 premiere of the BBC's "Sherlock" on PBS' "Masterpiece Mystery," most Americans will have to wait until Sunday, Jan. 19.
For executive producer Steven Moffat -- who helms both "Sherlock" and "Doctor Who" with the help of writer/actor Mark Gatiss (who plays Sherlock's brother, Mycroft Holmes) -- the goal is to make "three really good Sherlock Holmes stories. It's a very simple goal. I just want to make very good telecom films, which is quite challenging in itself."
It is interesting, though, that Moffat is finding success, not with something fresh and new and edgy, but with a detective created in the late 19th Century and a time-traveler who just hit 50.
"Nothing is a better test of success than endurance, is it?," says Moffat. "Perhaps it's not so surprising that 'Doctor Who' and Sherlock Holmes have been around for a long while. James Bond, 'Star Trek,' all those things ...
"You don't know what the greats are going to be until they survive a few decades. I suppose 'Robin Hood' has got them all trumped."
At the same time, these two venerable franchises are among the hottest things in social media -- and they get even hotter when you throw the Norse god Loki, who predates the Roman Empire.
Back in October, during a Reddit AMA (Ask Me Anything) session, "Sherlock" star Benedict Cumberbatch was asked the, er, cheeky question, "Do you, Matt Smith and Tom Hiddleston have cheekbone polishing parties?"
In case you've been living in a pop-culture cave, young Matt Smith was still playing the Doctor at the time, and "The Hollow Crown" star Tom Hiddleston has played Loki in the recent "Thor" and "Avengers" movies.
The droll, witty Cumberbatch replied, "We like nothing better than buffing our Zygoma. And imagining a horny time traveling long overcoat purple scarf wearing super sleuth nordic legend f*** fantasy. Get to work on that, Internet."
(A " zygoma" is a cheekbone, for those not familiar with Latin terms derived from Greek terms.)
A wave of weak knees and fluttering hearts broke across Reddit, then became a social-media tsunami of the vapors combined with overheated imaginations.
While Moffat does of course know who these men are, it appears he lives in a social-media cave, because he hadn't heard of the whole kerfuffle.
"No," Moffat says, then sighs. "I remember the days when we kept our fantasies to ourselves. I don't want to think about that. I don't know much about that kind of thing, but I'm very happy people do that, if it makes them happy."
Even though Smith has now been replaced by Peter Capaldi, don't expect to see him going zygoma-to-zygoma with Cumberbatch anytime soon.
"Nothing is impossible," Moffat says. "it's not something we're particularly striving for. There's enough inevitable crossover talk between those two, it might be disconcerting for either of them to appear in the other's show.
"If there was a perfect part for him, there's no rule against it. We wouldn't want it to be stunt casting, because stunt casting doesn't work, so it would have to be just because he was overwhelmingly right for it.
"I mean, I love working with Matt. He's a phenomenal actor. I'd jump at the chance to work with him again. I don't know how likely that is to be on the set of 'Sherlock.'"
Sherlock Holmes and Doctor Who have one other thing in common -- a sort of immortality and adaptability seldom seen outside characters from Shakespeare, the Bible or Greek mythology.
Not only have multiple actors played the roles in multiple venues and formats over multiple decades, but each was kept alive (or brought back from apparent death) because the fans couldn't get enough ... and neither could Sir Arthur Conan Doyle's publishers nor the BBC (or, since Moffat thinks "Sherlock" is likely to be renewed, now it's just the BBC).
"I don't know my history well enough," says Moffat, "but he didn't in fact bring (Holmes) back from the dead because of public outcry. He did in fact bring him back from the dead because of a very, very large check."
Asked if Doyle's action means Holmes set the stage for many fictional resurrections, including, for example, Bobby Ewing in "Dallas."
Says Moffat, "I'm sure he'd be personally appalled to know that."
Not many TV producers get to work on two megahits at once, and there are lessons to be learned.
Says Moffat, "I suppose one (lesson) is that, one thing I think a lot about, is work on the things that you love. Work on your passion projects. Don't work on what you think people would like to watch; just do something you'd like to watch.
"And in both occasions, Sherlock Holmes and 'Doctor Who,' these are just my favorite things. I love those. When I proposed the Sherlock Holmes series, we didn't think it was going to be a hit. We didn't do it because we thought it was going to be a huge international hit, which it has become.
"We thought it'd be a little art project, get some good reviews. It was a passion project. Don't do it because you think other people will like it; do it because you think you love it. If you do something you love, there's no guarantee that anyone else will love it, but ... at least you'll like it, and that's somebody who's pleased.
"If you do something everybody else likes, and nobody likes it, then nobody's happy, and what's the point?
"It's not arrogance. It's not a terrible thing when you say you know what you like. I know what I like, and I hope someone else likes it. On many occasions, believe me, no one else likes it."
Photo/Video credit: BBC