The producers of "Sherlock" have released the first official photo for the upcoming fourth season of the BBC series.

The image features Benedict Cumberbatch and Martin Freeman in their roles as Sherlock Holmes and John Watson, accompanied by the caption,"The boys will be back soon! Here’s the first official picture of #Sherlock and John from Series 4."

The boys will be back soon! Here’s the first official picture of #Sherlock and John from Series 4. pic.twitter.com/MqGfuUWb96

— Sherlock (@Sherlock221B) August 31, 2016

This photo follows the release of the promo trailer in July at Comic-Con International, which promised a darker tone for the next season, telling viewers that, "everything they know will be tested."

If you'll recall, the trailer teased several threads that will play out in Season 4: the possible return of Moriarty, the introduction of some new foes, and the revelation of some of Sherlock's secrets.

Followers of the series have been patiently waiting for more "Sherlock" since the end of Season 3, which aired in January 2014. Their hunger was briefly sated earlier this year, with the release of a special episode, "The Abominable Bride." While it was well received, it served mostly to whet the appetites of fans eager for more.

Season 4 is looking like it will take the show in a new direction. However, as series co-creator Steven Moffat told The Telegraph in July, this could be the final season produced for some time.

"Sherlock" Season 4 will likely air in early 2017 on BBC One and PBS.