The BBC has released the first official photo from Season 4 of Sherlock. The photo features Sherlock Holmes (Benedict Cumberbatch) and Dr. John Watson (Martin Freeman) looking sharp.
Sherlock Season 4 began filming in April 2016 and wrapped in August. Toby Jones has been cast in the season as a villain from Sherlock Holmes lore, though the show has not yet named the character. A trailer for the season was released at Comic-Con International: San Diego.
Sherlock has been on an extended hiatus since Season 3, which aired in 2014. The delay has largely been due to Cumberbatch and Freeman's schedules. Both have become in-demand movie stars, with Cumberbatch about to make his debut as Doctor Strange in the Marvel cinematic universe in November.
Sherlock Season 3 ended with the apparent resurrection of Sherlock's nemesis, the criminal mastermind James Moriarty. Sherlock was in the air on a plane set to take him into exile from the United Kingdom, but Moriarty's reemergence prompted his swift return.
The BBC aired a Sherlock New Year's Day 2016 special titled Sherlock: The Abominable Bride. The special took the modern versions of the characters from Sherlock and transplanted them to the Victorian era of Arthur Conan Doyle's original Sherlock Holmes tales. It was eventually revealed that the entire story of the Abominable Bride was taking place in Sherlock's "mind palace" while he was waiting to disembark the plane. Sherlock chose to revisit the Victorian murder he'd read about in order to figure out how he would have solved it because he believed it might help him figure out how Moriarty seemed to have returned from the dead.
Sherlock Season 4 premieres in 2016.