'Sherlock' Season 4 Release Date, News Update: Pregnant Mary Watson Betrays Benedict Cumberbatch? Moriarty, 3rd Holmes Brother Resurface In Action-Packed S4?

Heartbreaking "Sherlock Season 4" will give Benedict Cumberbatch a rough patch as Mary Watson (Amanda Abbington) is back to her old tricks and S4 throws Jim Moriarty (Andrew Scott) and third Holmes brother Sherrinford (possibly Tom Hiddleston) back into Sherlock's life. After over two years of waiting "Sherlock Season 4" brings back resolutions and more questions for Holmes (Benedict Cumberbatch) and best friend John Watson (Martin Freeman).

Comicbook cites an interview with Mary Watson actress Amanda Abbington and "Sherlock" producer Sue Vertue at the 2016 San Diego Comic Con. Sue Vertue reveals that "Sherlock Season 4" will be consistently heartbreaking with comedic breaks typical of Holmes and John Watson.

Interestingly, Amanda Abbington teased Mary Watson betraying Sherlock Holmes and John Watson in S4. "She lives up to her name," Amanda Abbington hinted on Mary Watson.

Amanda Abbington unveiled Mary Watson as an assassin who was after Holmes in the "Sherlock" series. Eventually, John and Mary Watson began to put the past behind.

The reveal now says Mary Watson could once more attempt betraying Holmes and John in "Sherlock Season 4." The timing couldn't have been more heartbreaking as John and Mary Watson are supposed to be pregnant in "Sherlock Season 4."

Comicbook further cites, and Parent Herald reports, that "Sherlock Season 4" will see both Jim Moriarty and third Holmes brother Sherrinford resurface into Sherlock's world. Holmes himself expects Jim Moriarty to bring mayhem back into "Sherlock Season 4" although this archenemy is dead.

Tom Hiddleston as the third Holmes brother Sherrinford (teased by series writer and Mycroft actor Mark Gatiss), seems to also be one ghost that will haunt "Sherlock Season 4." Because the reference to both the third Holmes brother Sherrinford and Tom Hiddleston had at best been ambiguous, "Sherlock Season 4" will have some shockers on reserve.

Unsurprisingly, "Sherlock Season 4" will be the darkest that the BBC series delved as CinemaBlend cites Benedict Cumberbatch saying. Suffice is to say that fans cannot hold onto any certainty about Mary Watson, Jim Moriarty, the third Holmes brother Sherrinford or even Tom Hiddleston until "Sherlock Season 4" premiere airs on BBC in January 2017.

Benedict Cumberbatch, Martin Freeman, Amanda Abbington, Andrew Scott, Tom Hiddleston will also be joined by new "Sherlock Season 4" villain Toby Jones as Culverton Smith. Which bets have you hedged for "Sherlock Season 4": Jim Moriarty return, reveal of the third Holmes brother, Tom Hiddleston as Sherrinford or Margaret Thatcher cameo?