'Sherlock' Season 4 Release Date & Spoilers: Set Ready For Filming, New Episodes By January 2017?

"Sherlock" Season 4 is definitely making a return and it's going to be bigger than it ever was before. Although filming has yet to begin, more details about the upcoming season of "Sherlock" have started to emerge.

"Sherlock" Season 4 is slated to begin filming this spring. Wales Online reports that the "Sherlock" cast and crew will be filming most scenes at Pinewood Studios in South Wales.

In fact, Christian Today has reported that one of the "Sherlock" production designers, Arwel Wyn Jones, has already shared some behind-the-scenes photos of the "Sherlock" Season 4 set on his Twitter account.

"We are going to try to take it somewhere we've never been before - and I don't mean outer space," Mark Gatiss, the show's writer and co-producer, told Entertainment Weekly in August 2014 with reference to "Sherlock" Season 4.

"We always start with a re-introduction that builds toward a darker climax - we might just be going darker [from the outset]. We got a very, very good set of ideas," Gatiss continued.

Although Benedict Cumberbatch is still busy filming Marvel's "Doctor Strange" around London, the "Star Trek Into Darkness" star will return to reprise his titular role as Sherlock Holmes, while Martin Freeman will be back as Sherlock Holmes' sidekick, Dr. John Watson.

Furthermore, the Christian Examiner claims that Moriarty, known as Sherlock Holmes' worst enemy, is rumored to be alive and will make a return for the show's fourth season.

Speculations also claim that a new character might be introduced in "Sherlock" season 4. The character, rumored to be Sherlock Holmes' third brother Sherrinford, is said to be portrayed by "Avengers" star Tom Hiddleston.

"Sherlock" Season 4 release date is slated for a January 2017 premiere.