Production is underway for BBC's hit series "Sherlock," and while the cast and crew have been keeping silent the details, there are enough stories, speculations and photos of the filming to give fans a clue on what the new season has in store, Venture Capital Post reported.
The last time fans got to see Sherlock Holmes and Dr. John Watson solve crimes together was more than a year ago, way back in January 2014. It's a pretty long time for a hiatus, and stars Benedict Cumberbatch and Martin Freeman have both been busy, but now season four is coming, just not as soon as fans hope.
A special Christmas episode will first be shown sometime in December, before a season four begins airing sometime in January 2016, according to The Guardian. That means there's around two years between seasons, which is quite a long wait.
While fans digest that info, here are some of the things they may be interested to know about the upcoming season of "Sherlock," and also some spoilers we've sourced online:
1. John and Sherlock now come with new costumes.
In November, BBC teased fans with images of the detective duo's Victorian-style clothing, showing Sherlock in a tophat and John with a moustache, according to The Guardian.
It not quite clear why a change in outfit is needed, and no doubt fans will miss Sherlock's trademark Burberry coat and John's no moustache face. However, it has been confirmed that it will be for the upcoming "Sherlock" Christmas special, so there's probably a good reason for it -- probably a fancy dress party or an event related to one of their cases.
2. Mary comes and goes.
John married the beautiful but secretive Mary Morstan during the previous season and now reports have it that in the fourth season, fans may have to say goodbye when tragedy strikes and Dr. Watson says goodbye to his wife, according to Venture Capital Post.
It's still too soon to call it, to be honest, but as readers of the original Sherlock novels are aware, Mary does die due to unspecified reasons. The BBC series has been faithful in some parts to the novels, and this just might be one of those times.
3. Detective Inspector Greg Lestrade and Molly Hooper are here to help.
There is limited news on just who will be appearing on the show aside from Cumberbatch and Freeman. However, some familiar faces and friends are expected to return, such as Rupert Graves as Lestrade and Louise Brealey as Molly.
It's also likely that Sherlock's well-loved landlady Mrs. Hudson, played by Una Stubbs, will pop up once in a while and also Sherlock's brother Mycroft Holmes, played by Mark Gatiss, who is also the series co-creator and writer.
4. Moriarty returns.
Andrew Scott is coming back to reprise his role as Sherlock's greatest nemesis, and BBC even posted a teaser photo about it, showing Jim Moriarty on a television screen and the words "Miss Me?" according to Variety.
Apparently, villains never die -- even Jim Moriarty -- despite having committed suicide by shooting himself through the head right in front of Sherlock during the end of season two. Then again, Sherlock came back to life as well, so this probably isn't a surprise.
Scott is confirmed to be appearing in the upcoming Christmas special, which will explain his reappearance and also clear the way for the new arc in season four.
5. It's going to get darker.
Co-creator and writer Steven Moffat revealed that season four is darker and going further than the previous season, according to IBTimes.
"We have a plan to top season three, and I do think our plan is devastating," he said. "We've practically reduced our cast to tears telling them the plan."
Gatiss agreed, saying, "We always start with a re-introduction that builds towards a darker climax. We might just be going darker. We got a very, very good set of ideas."