When the Sherlock holiday special was first announced, fans were initially delighted at the thought of a story set in Arthur Conan Doyle's original 19th Century setting.

But the more you think about it, you can't help wondering if it's just a gimmick. Showrunner Steven Moffat has already confirmed it's set outside the show's continuity, so... End of the day, what's the point? Isn't it just going to be silly riffs on the classic Holmes tropes?

If this trailer is any indication, Moffat and his cast and crew are taking it very seriously. "The Abominable Bride" is its title, and unfortunately we don't have an official synopsis yet. The trailer, while exciting and fun, doesn't drop very many clues about the plot, either, aside from what appears to be a dead bride in one shot.

What really jumps out at you is how the trailer emphasizes the characters' reverting to the speech patterns, names, and habits that were part of Doyle's original stories. Instead of Sherlock and John, the two leads call each other Holmes and Watson, for example, and Holmes clutches his smoking pipe between his teeth. Holmes plays his violin. Watson speaks to him as a friend who's known him for many years.

More than anything, what the trailer proves is just how brilliantly watchable the duo of Benedict Cumberbatch and Martin Freeman are — no matter the setting.

The best bit comes at the end when Watson suggests a hat for Holmes to wear. It's too good to spoil. Just watch.

Sherlock: "The Abominable Bride" will premiere in both the U.S. and the U.K. on January 1, 2016. Like all Sherlock episodes, it's expected to run for 90 minutes. Shooting on the show's fourth season is expected to begin in the spring.

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