Sherlock is back, and it looks like along with its new storyline it will also excite its fans by introducing new characters. Latest "Sherlock" Season 4 spoilers indicate that the third brother or perhaps sister, Sherrinford Holmes may soon be seen in the television series.

The first hints of Sherrinford Holmes were given at the end of the third season when Mycroft said, "I'm not given to outbursts of brotherly compassion. You know what happened to the other one." This gave rise to the possibility of the third Sherlock brother or sister, as reported by Just Jared.

"Sherlock" Season 4 Spoilers now suggest that the third Holmes would be Sherrinford Holmes and could be played by Tom Hiddleston. The story goes that Sherrinford was in the Sir Arthur Conan Doyle's list of potential names for the character of Sherlock.

In the fictional biography of Holmes by William S. Baring-Gould, Sherrinford was the eldest brother who stayed back to manage the family estate, as Den of geek.

A tweet from Mark Gatiss may have confirmed these "Sherlock" Season 4 spoilers. He tweeted a picture with Tom Hiddleston and Amanda Abbington. In the same tweet, it read, "Blud," which is basically slang for "brother."

It is worth noting that IMDB page of "Sherlock" season 4 does not feature Tom Hiddleston in the cast list. In the latest episode of "Sherlock" Season 4 "The Six Thatchers," there was the biggest reference to Sherrinford.

Mycroft notices a message "13th" on his fridge and decides to make a call. During the call, he says, "I need to speak with Sherrinford. Yes, I'll wait." Fans of the show know when Mycroft is ready to wait, the other person will be very important and probably family.

Some "Sherlock" Season 4 Spoilers also point out that Sherrinford could be Mycroft's son or daughter. Makes sense, he had called at a school and had to wait. At this point, all these are mere speculations and theories.

Who do you think is Sherrinford? Will Tom Hiddleston be seen in "Sherlock" Season 4? Let us know in the comments section below.