WATCH: Benedict Cumberbatch wows in the brand new trailer for Sherlock series 4
The game is afoot... and from the looks of things, it looks a lot less friendly now.
The BBC has confirmed that Baker Street's favourite double act, Benedict Cumberbatch and Martin Freeman, will be back on our TV screens from the 1st of January 2017.
As diehard fans will remember, Sherlock finished series 3 on the verge of exile, only to be recalled to the United Kingdom when every video screen in London broadcast an image of Moriarty.
Going by the looks of the updated trailer, Sherlock might end up wishing that he had stayed on that plane...
As you can see, there will be an awful amount of shooting and brooding in Sherlock series four as a lot of eggs come home to roost for Holmes and Watson.
Fans will already know that the opening two episodes of the fourth run are called 'The Six Thatchers' and 'The Lying Detective', and that new stubbled look for Benedict Cumberbatch will be more than just a fashion choice.
Sherlock will be put through the wringer this time, facing off against a new unknown villain, (please be Colonel Sebastian Moran) played by actor Toby Jones.
Eagle eyed fans will also spot a lot of interesting shots of what looks to be the return of arch-nemesis Moriarty, as well as what could be some flashback scenes involving Watson's wife Mary from her days as an assassin.
That the trailer is capped off with a clash between Mrs Hudson and Mycroft Holmes only underlines things - Sherlock series four is playing for keeps, and things will be rather explosive.
As Moriarty asked right at the end of series three - "Did you miss me?"
Going by this trailer the answer is a resounding yes. We'll be sure to be Sherlocked when the series returns to the BBC on New Year's Day.