In the final moments of "Sherlock" Season 3 finale, Moriarty popped up on T.V. screens all across the country, asking "did you miss me." Moriarty's return on the T.V. screens was a well-planned twist, and not at all a last minute addition. Andrew Scott, who plays Moriarty, has said that he knows the truth about Moriarty's twist. However, he did not spill the much speculated spoiler.
In an interview with DigitalSpy, Scott said, ""I do know the answer to that question, yes, and I'm not going to tell you!" Mark Gatiss and Steven Moffat, co-creators of "Sherlock," have confirmed that Moriarty will feature in Season 4 of "Sherlock." They have a proper explanation for his appearance in the final moments of Season 3.
The writing duo has already mapped out the Season 4 and Season 5 of "Sherlock." In the new season, new characters are expected to be introduced. Gatiss had said, as reported by The Hollywood Reporter, that moving forward they intend to keep "Sherlock" new and introduce new characters. Also, the upcoming seasons will show Sherlock's "gradual humanization." The Season 3 also showed Sherlock's more human side, because of his best-friend Watson. Watson's wife, Mary Watson, is very much part of Season 4.
Will another brother of Sherlock arrive in Season 4? In Season 3 finale, "His Last Vow," Mycroft had alluded to there being another brother. Without revealing anything about this brother, Moffat had said in an interview, ""Wait and see!" when asked about the role of this unknown brother in the future season of "Sherlock."
Like Season 3, "Sherlock" Season 4 is expected to take almost two years to premiere. Gattis has almost confirmed that Season 4 is likely to air in 2016.
Responding to the news that "Sherlock" Season 4 may premiere in 2016, Gatiss had said to Metro, "There was suddenly a kind of outraged response that it might not be back until 2016 but that's precisely how long it always is. It's always two years! But we'd like to return soon, of course."