Sherlock season 4: Trailer confirms when Benedict Cumberbatch's detective will return

The actor has long been hinting that this season may be the last for Sherlock and Dr. Watson

With barely a moment to recover from the results of The Great British Bake Off final, the BBC revealed when another beloved British property will be returning to screens.

The previously released trailer for Sherlock season 4 was aired, marked with one crucial difference: we've finally gotten an air date for the new episodes, premiering on 1 January 2017. And there's plenty at stake this time around, with Benedict Cumberbatch's usually unflappable detective looking uncharacteristically distressed.

"Something's coming. Maybe it's Moriarty. Maybe it's not," the dialogue echoes; which perhaps may nod to the highly-rumoured return of Andrew Scott's villain, or hint at the threat posed by Toby Jones' Culverton Smith. With Episode 2's title revealed to be 'The Lying Detective', there's a hint that the series may be adapting Arthur Conan Doyle's tale 'The Dying Detective'.

The story sees sees Holmes convince Watson and co. that he's dying of a rare disease in order to entrap Culverton Smith into confessing to his nephew's murder; with Jones' involvement presumably seeing some sort of spin on the classic tale.

Fans will certainly be anxious to know how this season ends, with Benedict Cumberbatch strongly hinting that season 4 of Sherlock will be its last; commenting that wrapping shooting felt like, "the end of an era".

Sherlock season 4 premieres 1 January 2017 on BBC One.