It's been nearly two years since the last episode of 'Sherlock' was aired, and fans have been waiting patiently for the assured next instalment. The excitement started building when it was announced that it would be a one-off Victorian edition, and now the new teaser for 'The Abominable Bride' has been released, the New Year can't come soon enough.

SherlockBenedict Cumberbatch and Martin Freeman return in Sherlock special

It seems Benedict Cumberbatch doesn't just apply Holmes to the modern world with finesse, but also embodies the traditional deerstalker-donning detective with jaw-dropping accuracy - that's if the new trailer is anything to go by. In this latest clip we see a veiled assassin emerging from a horse-drawn carriage with a shotgun; a supposed figure of a dead woman who Sherlock eerily dubs 'the avenging ghost'.

Watch the trailer for 'The Abominable Bride' here:

Of course, it's unlikely that 'Sherlock' has finally ventured into the supernatural, bringing dead brides back to life and all, and the question that needs solving here appears to be: 'Who was the bride?' Is this a 'Kill Bill' style act of vengeance by a woman who managed to only narrowly escape death? Or is this mysterious masked killer someone entirely different? A 19th century Moriarty in a dress perhaps? Which isn't an entirely improbable proposition in regards to this effeminate villain.

Clues may normally appear in the original Sir Arthur Conan Doyle stories, but the subject is only alluded to in a throwaway comment from 'The Musgrave Ritual', in which Sherlock talks about 'Ricoletti of the club foot and his abominable wife'.

More: Here's what we know so far about 'The Abominable Bride'

Whatever we're dealing with, Martin Freeman has that moustache back again for Watson and it suits him much better in this 1885 setting.

'Sherlock: The Abominable Bride' is set to air on January 1st 2016 via BBC One and PBS. For those die-hard fans who want to make a celebration of it, it will also be appearing in selected cinemas for one night only.