Almost a year since our last fix of Sherlock, and we are finally getting a glimpse at what Mark Gatiss and Steven Moffat have in store for us. The fourth season of course sees the return of Benedict Cumberbatch and Martin Freeman (Sherlock Holmes and John Watson respectively), as well as Una Stubbs as Mrs Hudson, Mark Gatiss as Mycroft Holmes and Rupert Graves as D.I. Lestrade.
The teaser also gives us a look at new character Culverton Smith (Toby Jones), who will also serve as this seasons antagonist.
The new episodes of Sherlock will hit television screens on 1 January, 2017.