It has been a long and tortuous wait for fans of private detective Sherlock Holmes, but now, after a two year hiatus, filming for series 4 has finally begun.

The first picture from the series 4 set was released, and it shows our favourite detective consulting man's best friend, more commonly referred to as a 'dog,' which is actually cannon with Sir Arthur Conan Doyle's novels.

If a series 4 promo image is anything to go by, the start of the season will open with a very haggard looking Sherlock Holmes. This is out of character for the meticulous sleuth, so many speculate that the problems Sherlock will be facing this season will be more difficult than the ones he has faced in the past.

Sherlock's old nemesis Moriarty (Andrew Scott) is rumoured to resurface this series, and the distressed look of Sherlock substantiates this belief - no other foe has ever made the private eye look so ragged in appearance the way Moriarty does.

A new enemy joins the cast, as well, and he will be played by Toby Jones. The actor has not confirmed any details about his character, but he did say that he was definitely one of the bad guys.

Many are speculating about who Jones could be portraying this season, but fans will have to wait until January of 2017 to find out for sure, which is the tentative release date for the new series.