'Sherlock' Season 4 Air Date & Premiere Spoilers: 3 Plot Rumors Revealed So Far

The season 4 of the highly popular BBC television drama, "Sherlock," has been moved to two years from its original run of early 2015 to early 2017.

Many fans were shocked upon learning that the season 4 of "Sherlock" will be moved. The Digital Spy reported that Steven Moffat has announced that the 4th season will begin filming in spring of next year.

Each season is composed of three episodes, and judging from the pattern of the release dates for the past seasons, Latin Post predicts that the season 4 premiere may be on Jan 1, 2017.

Here are some plot rumors for "Sherlock" season 4:

1.) "Darker" and more dramatic than season 3

When showrunner Steven Moffat was asked about the upcoming episodes for season 4, he said that it will be "devastating."

"We have a plan to top (season three)," Moffat said in a report by the Independent.  "I do think our plan is devastating. We've practically reduced our cast to tears telling them the plan...we're probably more excited than we've ever been about Sherlock."

During the recent Comic Con panel, Moffat added that the show will have a lot of cliffies as well.

"We know very, very clearly what stories we're doing," Moffat said in a report by International Business Times. "Where each episode goes, what the shattering, emotionally draining, you'll never be the same again and you'll never stop crying cliffhangers will be."

2.) Jim Moriarty may come back

Although Moffat has been reported as saying that Moriarity is already dead, iDigital Times alleges that Moffat may have been tricking fans and that the "consulting criminal" may have faked his own death. After all, fans have seen Moriarty's extensive connections and what he could do; faking his own death could be a piece of cake for the criminal mastermind.

3.) Another Holmes brother may appear and it could be played by Tom Hiddleston

Crossmap reports that Mycroft and Sherlock may have another brother or sister. In the scene where Mycroft reprimanded a punishment and brotherly bias for Sherlock in season 3, the former mentioned a line ("You know what happened with the other one") that suggests that the two may have another sibling. Most interestingly, it is rumored that it would be played by "Avengers" actor Tom Hiddleston.

To make up for the delay of the fourth season, the showrunners are treating its fans worldwide to a "Sherlock" Season 4 Christmas Special this year. The standalone episode will be set in the Victorian era, when the books by the original author Sir Arthur Conan Doyle were written originally, Breathe Cast reports.