Sherlock has been testing the patience of its fans over the past two years and counting, but season 4 looks like it will be well worth the wait. The first teaser hit the internet today and showed signs of a dark and dangerous mystery — one that possibly involves a villain thought to be dead.

Stars Benedict Cumberbatch and Martin Freeman return as the crime-solving duo of Sherlock Holmes and Dr. John Watson. As always, it is unclear what they are up against: “Something’s coming,” teases the video. “Maybe it’s Moriarty, maybe it’s not.”

Moriarty (played by Andrew Scott) does appear briefly in the teaser, but since he is supposed to be dead, it is hard to say what role he will play in the upcoming season. At least one villainous role is reportedly being filled by actor Toby Jones; he certainly has the madman laugh down pat in the preview.

No matter who is stirring up trouble next in the world of Sherlock, they’re doing a good job of it. The teaser is an intense one, featuring explosions, helicopters, and what looks like a car chase.  “It’s not a game,” we’re told. Clearly not.

With so much up in the air, there is only one question we can answer after watching the video: “Did you miss me?” The series has definitely been missed; by the time season 4 premieres, it will have been a year since the most recent special, Sherlock: The Abominable Bride, and three years since the conclusion of season 3.

Season 4 is clearly going to be a big one, and it should be one to savor. Co-creator Steven Moffat recently revealed the possibility that the upcoming season could be the last.

Sherlock season 4 is set to premiere in 2017.