Watch: Benedict Cumberbatch And Martin Freeman Step Into The 19th Century In New Trailer For The 'Sherlock' Special

This holiday season, after the presents are unwrapped, the eggnog quaffed, and roast beast devoured, BBC One will have a mystery ready for you to solve. Some of the small screen's most beloved sleuths —  Sherlock (Benedict Cumberbatch) and Watson (Martin Freeman) — are back with a special episode of "Sherlock," and a new trailer has arrived to give you a little peek at what's coming.

READ MORE: Watch: First Clip From Victorian-Set 'Sherlock'

As fans already know, this special edition entry offers a bit of a twist, taking the characters back to 19th century England, the original setting of Sir Arthur Conan Doyle's stories about the famed detective. There, Sherlock and Watson will get embroiled in an "impossible" case, featuring no shortage of intrigue, snappy dialogue, and even snappier hats.

"Sherlock" returns sometime in December, but no firm dates have yet been announced. Watch below. [Shortlist]