It's not long now until we'll see Sherlock Holmes (Benedict Cumberbatch) and Dr. John Watson (Martin Freeman) transported to 1890s Victorian London to solve a murder mystery in the 90-minute one-off "Sherlock" special, "The Abominable Bride."
But taking a modern-day show and placing it back in its original setting is both a fun experiment and a challenge for the "Sherlock" cast and crew. They reveal what the experience has been like in a new BBC behind-the-scenes video.
"I suppose we can boast and say we've got the Sherlock Holmes and Dr. Watson of this current time," series creator Steven Moffat said in the video.
"Part of the impulse came from me and Mark [Gatiss] saying 'Wouldn't it be a shame if we never got to see them do it in the authentic setting?'" Moffat added. "So it was irresistible to do a special that is Victorian."
"I think Victorian London and all the sort of trappings of that era are endlessly fascinating," Cumberbatch says in the video. "The sort of ghoulish, nightmarish, fog-laden dark corners and alleyways. The dampness the sort of whole kind of claustrophobic night world that he inhabits, it's a masterful lens on that whole era as well."
New pictures reveal more clues from 'Sherlock' Victorian specialSee all photos
The setting for this "Sherlock" special isn't the only big change fans will have a chance to experience. It also sounds as though we might get a more jovial and amiable version of Sherlock Holmes as opposed to the somewhat tactless and selfish Sherlock we've grown accustomed to in the modern-day series.
Una Stubbs -- who plays Mrs. Hudson -- said that fans will love the special because, "it's a very affectionate, amusing Sherlock."
"Sherlock: The Abominable Bride" will air on January 1, both on BBC One in the UK and on PBS in the US. It will also get a theatrical release in select venues around the world.