After 18 long months since the end of season 2, BBC’s runaway hit drama Sherlock is finally ready to return to our screens this fall, with leads Benedict Cumberbatch and Martin Freeman happily taking time off from their heavy movie schedules to reunite as detective duo Sherlock Holmes and John Watson.

This isn’t just any reunion, however; as season 3 begins, John will be fully convinced that his friend is dead, having seen him supposedly throw himself off the roof of a building in “The Reichenbach Fall.” It’s unclear how much time has passed between the second and third season, but it’s safe to say that when the two old friends meet once more, they’ll have a lot of issues to work through.

The BBC has finally decided to end the silence by releasing the first promotional teaser for season 3 of Sherlock, though it should be noted that it does not contain any actual footage from the show. Instead, the teaser hypes the return of Sherlock into the lives of the various friends he has managed to acquire over the years, as well as his brother Mycroft (played by co-creator Mark Gatiss), and throws a stunning reveal at the audience.

If there was one thing liable to make Sherlock fans freak out more than the trailer itself, it’s the sight of Freeman finally succumbing to the classic portrayals of Watson and donning one of the staples of his usual appearance. Again, since this isn’t footage from the show it’s hard to tell whether this is something that actually happens, or just thrown in for added impact. If the former, it’s really quite understandable. Trauma does have a tendency to push people towards strange, rebellious or even downright dangerous lifestyle choices, and it seems that John has found his: he’s grown a mustache.

Freeman actually wears it quite well, but its existence does allow for a rather amusing alternative interpretation of the final shot of the teaser. Does Sherlock look shocked and upset because he’s about to meet his best friend again after so long, or because he’s just so appalled by the moustache? Either way, it’s probably not wise to get too attached to it, as only a very small number of the set photos so far have shown Freeman sporting facial hair. It looks like this may only be a temporary measure.

It’s difficult to glean any real clues about the first episode of Sherlock season 3, “The Empty Hearse,” without getting a look at the real footage, so for now just enjoy this brief but effective teaser and pray that we’ll get to see more soon. One especially exciting aspect of this season is the introduction of a new villain, Charles Augustus Magnussen (Lars Mikkelsen), who is described in Arthur Conan Doyle’s short story as the most repulsive man that Holmes ever met.

[UPDATE: Interest in this video just went up a notch, as despite earlier reports that the footage was shot only as a teaser, Mark Gatiss has confirmed on Twitter that everything you see above is actually from season 3 episodes. Start taking  closer look at it for hints of what’s to come.]

Let us know in the comments what you expect to happen when Sherlock and John finally meet again.

Sherlock returns to the BBC in fall 2013 and to PBS some time in 2014.