Rumors have surfaced that "Thor" star Tom Hiddleston will be the third Holmes brother in "Sherlock" Season 4 while cast member Andrew Scott has also been rumored to resurrect his character James Moriarty in "Sherlock" Season 4. Also, series creator Steven Moffat revealed some plot details of the upcoming season which is set to premiere around January 2017.

Rumor has it that "Thor" star Tom Hiddleston has landed a major role in the upcoming 4th installment of "Sherlock". According to Parent Herald, the 35-year-old English actor has been cast as Sherlock (Benedict Cumberbatch) and Mycroft (Mark Gatiss) Holmes third brother, Sherrinford. The said rumors stemmed from fans and viewers alike who are hoping for an English actor to be a part of the show alongside Benedict Cumberbatch as the titular hero, and Martin Freeman as John Watson.

It also turns out that series co-creators Steven Moffat and Mark Gatiss are hoping that the casting deal will push through to have an English actor on board.

In addition, cast member Andrew Scott has been rumored as well to return in the upcoming season. The 39-year-old Irish film, television, and stage actor is reported to resurrect his role as Professor James Moriarty, Christian Today has cited.

Series creator Steven Moffat teased some details via Den of Geek on what fans should expect in the upcoming episodes of "Sherlock" Season 4.

Moffat stated, "We do address the outstanding issues. Possible contenders, Mary's mysterious past, the third Holmes brother, and of course that viral 'Miss Me?' video featuring Moriarty's face. I think there's still an ongoing element that people haven't really picked up on... I think there's stuff to come."

Production and filming for "Sherlock" Season 4 will begin this Spring and the series is expected to premiere around January 2017.

"Sherlock" is a British-American crime drama TV series created by Steven Moffat and Mark Gatiss. The storyline is based on Sir Arthur Conan Doyle's detective stories "Sherlock Holmes".