The game is (still) afoot, and to prove it, BBC has dropped a new trailer for the fourth season of the global hit Sherlock. Coming off the tumultuous events of Season 3 (and the 2016 holiday special The Abominable Bride), Season 4 looks to test the world’s first consulting detective and his friends like never before, with new main villain Toby Jones looking especially menacing in the footage so far released. Watch the trailer above.

Of course, plot details are still very much under wraps, but clues were given last summer at Comic-Con when co-creators Mark Gatis and Steven Moffat provided three names: Thatcher, Smith and Sherrinford. That first name rather mundanely refers to the title of the season 4 premiere, “The Six Thatchers.” But that third name holds crucial importance for Holmesians. It originated as the name Arthur Conan Doyle toyed with before settling on Sherlock, later revived by noted Sherlock Holmes scholar William S Baring-Gould as the name of a hypothetical older Holmes brother. Does this mean Jones will be playing Sherrinford? Cue dramatic pause and cliffhanger-appropriate music.

Starring Benedict Cumberbatch as Holmes, Martin Freeman as John Watson, alongside Rupert Graves, Una Stubbs, Mark Gatiss, Louise Brealey, and Amanda Abbington, Sherlock season four kicks off with The Six Thatchers on January 1.

Of interest – in a first for the series, The Six Thatchers will premiere on the same day in the U.S. and the U.K.. That’s a very smart move considering the huge popularity of the series globally (especially in the United States). Previous seasons have seen international premieres as much as three weeks after the UK bow, a huge window for pirates to do their thing. Good move, in other words.