‘Sherlock’ Season 4 Air Date, Spoilers, News, and Update: Who Is Sherrinford Holmes? Watch the Intriguing Trailer

In the last episode of "Sherlock," co-creator Mark Gatiss who also plays the role of Mycroft Holmes gave fans a hint. Mycroft's line, "I'm not given to outbursts of brotherly compassion. You know what happened to the other one," led fans to expect the appearance of their third brother Sherrinford Holmes on the next season of the hit crime drama “Sherlock.” But who will play the third brother Sherrinford Holmes?

During last July’s Comic-Con in San Diego, Mark Gatiss (Mycroft Holmes) and Amanda Abbington (Mary Morstan) were seen posing for a photo with Tom Hiddleston. This sparked speculations among fans whether Tom Hiddleston will be playing the third brother Sherrinford. To things more interesting, Mark Gatiss posted the photo on Twitter with a caption "Blud."

Blud. #SDCC16 pic.twitter.com/T2lGDBQMzv

— Mark Gatiss (@Markgatiss) July 25, 2016

Responding to all the speculations, BBC teased the fans by fusing the clips of Benedict Cumberbatch in "Sherlock" with Tom Hiddleston in the "Night Manager." When the video was released, the buzz for "Hiddlebatch" tandem for "Sherlock" season 4 went crazy.

Radio Times asked Benedict Cumberbatch (Sherlock Holmes), during his interview, if he enjoyed working with Tom Hiddleston. He playfully answered if they were referring to the crossover of his movie "Doctor Strange" to "Thor: Ragnarok." Cumberbatch continued that he enjoyed working with Tom Hiddleston but as Loki and not as Sherrinford.

Showing some hesitation to divulge clues about "Sherlock" season 4, Benedict Cumberbatch was asked upfront on whether Tom Hiddleston will be part of the much awaited season 4. He merely replied that it is only pure speculation.

The premiere of the much anticipated "Sherlock" season 4 is set to air on January 1, 2017, on BBC. It's only a matter of time before the show starts to give us more solid evidence as to who will play Sherrinford Holmes. As of the moment, fans are left to wonder whether Hiddlebatch tandem is a possibility.

Meanwhile, BBC released a new teaser of "Sherlock" season 4 and it looks like an intriguing dark season coming up next year.

What do you think will happen in the upcoming season? Share your thoughts and comments below!