It turns out that taking the BBC’s modern version of Sherlock back to its Victorian roots is not the easiest project in the world. In the video above, you can watch creator Steven Moffat and stars Benedict Cumberbatch and Martin Freeman discuss the challenges of returning Doyle’s story its origins in 19th-century London, with all the attendant changes in communication, decor, hairstyle, and—of course—famous hats.
The special, called Sherlock: The Abominable Bride, will air on Jan. 1 on the BBC, and in the U.S. on PBS at 9:00 p.m (and online at pbs.org/masterpiece). It will be a standalone episode—the fourth season is expected to air in 2017—and will run for 90 minutes. Watch the trailer for the episode below.