Fan girls around the globe are thrilled at the very idea that "Sherlock" may include a third Holmes brother played by none other than Tom Hiddleston.

It can be recalled that Mycroft Holmes alluded to a third Holmes brother in the previous season of "Sherlock." Now, rumor has it that Hiddleston may be playing the part in the fourth season. If the rumor proves to be true, this will be Hiddleston and Benedict Cumberbatch's first on-screen reunion since appearing together in Steven Spielberg's "War Horse" (2011).

As previously reported, co-creators Steven Moffat and Mark Gatiss, who also happens to play Mycroft, teased the fourth season using three words at the San Diego Comic-Con: Smith, Thatcher, and Sherrinford.

For those who are unaware, Sherrinford is the name that author Sir Arthur Conan Doyle considered for the lead detective before eventually settling with Sherlock. It is possible that Sherrinford may be brought to life in the new season as the third Holmes brother. And given that BBC has already revealed two out of three episode titles, the third episode may be under wraps for good reason.

In other news, Cumberbatch recently stirred the "Sherlock" fanbase when he pointed out in an interview that the fourth season of the series may be "the end of an era." Although he did not explicitly say that season 4 would be it for the show, it did spark widespread speculation that it could be the final installment.

However, Moffat recently voiced his opinion on the matter and shut down rumors that season 4 would be the last. "If you just look at what (Benedict) actually says, he says nothing of the kind. He actually says he's very keen to carry on playing Sherlock Holmes," the co-creator said, according to news.com.au.

"We haven't talked to the BBC about another run. It's the clickbait era turning something that was nothing at all into a story," he continued.

"Sherlock" season 4 will premiere in 2017.