Holmesians may not like the spoilers below. Proceed with caution and please remember - it is just a TV show......even if it is one of the best going around!
Sherlockians, on the other hand, rejoice!! Sherlock is going to go to "unexpected" places next season and will be "darker" and deeper than ever before.
Watson Becomes a Father
First off, the heartwarming news that Mary and John's baby will be part of season 4. Amanda Abbington, who plays Mary, gives the assassin-turned-good a loveable, funny personality that makes it believable that her and John can get past the problem of her formerly 'secret identity'. It will be a nice addition to the group to have a little baby around, and John, Mary and Sherlock will make for an interesting parenting team.
But will Mary Survive?
Steven Moffat, a producer of the show, has told fans to "expect tragedy as well as adventure".
So fans should not get too excited about this new family unit, as it probably won't last long.
As all true Holmesians would already know, in Arthur Conan Doyle's books, Mary does not live for more than a few years after her marriage to John (approximately 5 from what I can gather). Conan Doyle does not specify how she passes away, she is simply no longer alive in "The Adventure of the Norwood Builder" and John has returned to Baker Street to live with Sherlock. Moffat has even confirmed that "at some point presumably she'll die".
But, given the love fans of the BBC series have for Mary and John (Martin Freeman), and the lack of strong female characters in the series (something for which writers have received criticism over the years), Mary may just make it through season 4. Fingers crossed!
Female Perspectives on Sherlock
A stand out character from all three seasons, despite only having featured in two episodes, has been Irene Adler (Lara Pulver).
We first met Adler in this intriguing scene -
Although Adler is not a major character in the books, and has featured more prominently in derivative works than she did in the Conan Doyle series, we may get to see more of Pulver's Irene.
Moffat said that female perspectives will be more apparent in season 4, as he believes they provide an "illuminating" insight into Sherlock Holmes and his work. Molly Hooper (Louise Brealey) will continue to be an important person in Sherlock's life and Mrs Hudson (Una Stubbs) will appear more often in the next few episodes.
Janine (Yasmine Akram), who became a potential love interest for Sherlock last season, will also appear in season 4 said Moffat, but simply as a friend that Sherlock can call up when he "needs a date", not as his girlfriend, since he is only interested in being 'pals'.
Will Sherlock Get a Second Brother - Sherrinford?
Mycroft (Mark Gatiss, who is also a co-creator of the series) is a highlight of the show and provides interesting insights into Sherlock's childhood and behavior. Could season 4 see the appearance of another brother, Sherrrinford?
Sherrinford was not in Conan Doyle's books, but was created by William S. Baring-Gould, a noted Sherlock Holmes scholar that believed the facts Conan Doyle outlined about Sherlock and Mycroft pointed towards the existence of an older brother.
Whether or not Moffat and Gatiss will decide to stir up trouble with Holmesians by including this 'fake' Sherlock character is yet to be seen. The rumor mill has gone wild with speculation that Tom Hiddleston, who stars as Loki in [The Avengers](movie:9040), could join his good friend Benedict Cumberbatch in the series by becoming this long-lost sibling.
A hint that many Sherlock fans have clung to since season 3 finished has been the conversation Mycroft and Sherlock had in 'His Last Vow'. Mycroft dropped the following bombshell:
“I’m not given to outbursts of brotherly compassion. You know what happened to the other one.”
Was this a not so subtle hint that Sherrinford is on his way to Baker Street? Or was it the writers just playing tricks on us? We might just have to wait and see, since no one is willing to deny or confirm at this point.
All Gatiss was willing to say was "“Well it’s an internet rumour so it must be true." Not particularly promising, is it?
Season 5 of Sherlock Already Underway
Whether or not we lose Mary, whether or not Sherlock gets another brother, at least we can be sure that Gatiss and Moffat are preparing to make at least a fifth season of the hit show!
Gatiss even told Reddit users that the pair have already started brainstorming for a 5th installment and have plenty of great ideas for crimes and adventures that Watson and Holmes can enjoy. In fact, he singled out 'The Adventure of the Red-Headed League' as the book from the Conan Doyle series that he would most like to tackle in the future. So if you are a big Sherlock fan with flaming locks, perhaps you should brush up on your Londoner accent in time for casting?!
What do you want to see happen in season 4 of [Sherlock](series:201416)? I ignored the Christmas special this time, cause it has already generated enough attention and is separate from the main story, but if you are more excited about that time-travel ep, we can also discuss that in the comment.