In the previous season of "Sherlock," it said that the Holmes brothers have another sibling which it will reveal soon. There are swirling rumors that Tom Hiddleston will play the role of this certain sibling.

According to Crossmap, reports have began to emerge when a Q&A started by the showrunner have surfaced. However, Mark Gatiss, who already played the other brother Mycroft Holmes, is not spilling the beans yet if the said new character will join the upcoming fourth season.

In fact, Benedict Cumberbatch, Sherlock Holmes himself, revealed in his recent interview that fans will get to know more of his family in the next installment. "You find out about Sherlock's background. You find out that he comes from a truly stable home," he said.

"It was a gesture in the first episode, but you see that in practice in the third. You see that, as a boy he was deeply insecure—it begins as a taunt from his older brother Mycroft," the 39-year-old star added. "...and that comes back to haunt him and he feels like a child. He's reduced to feeling like a child,' he continued."

Meanwhile, Parent Herald cited confirmation that Cumberbatch and Martin Freeman will, of course, reprise their roles. Also, Amanda Abbington as Mary Watson, Jonathan Aris as Anderson and Louise Brealey as Molly Hopper will be joining them.

Furthermore, the executive producer asserted that the recent "Sherlock" special "The Abominable Bride," released on New Year, has no connection with Season 4's plot. "We wouldn't have done the story we're doing and the way we're doing it if we didn't have this special. It's not part of the run of three episodes," he said.

However, Steven Moffat teased the show's fans as he said that the forthcoming episodes will be very different compared to the previous seasons that viewers used to see. He enticed their supporters when he unveiled that it's darker in some ways, exhilarating and will face a lot of consequences that spectators will cry to see Season 5 instantly.