In just four days, the long-awaited fourth series of BBC’s hit show Sherlock will premiere on BBC One. Happy new year for fans, indeed. But will series four itself be happy? Many a sign points to “no, not really.” Riveting, certainly. Dark? Undoubtedly. The mythology of Sherlock Holmes promises to expand during the episodes, but where will that leave our Holmes and Watson duo?

Of course, only watching the episodes will tell. But as speculation is part of the fun of being a fan, here are four of my predictions for series four. (See my theme yet?)

1.) Trouble in paradise

Things may not be all sunshine and puppies for Mr. and Mrs. Watson. Although we will see the arrival of their baby, Rosamund Watson, several signs point to an unhappy marriage. Our first clue is canonical. Mary Watson dies in the ACD stories. In our series, she may or may not die, but something will undoubtedly happen in the line of duty—remember, she was a spy. Or something. We didn’t exactly get the details that were on the mysterious thumb drive. But at any rate, the two largest suggestions can be found in the promo photos (where John and Mary appear at odds, with John carrying the baby) and in the very sad reality of Martin Freeman and Amanda Abbington’s real-life split after 15 years of partnership. Amanda intimated in an interview that it was strange to play the part of Mary to Martin’s John at this point in their lives because the story appeared reflective of what was occurring to them personally.

2.) The other one

Blud. #SDCC16 pic.twitter.com/T2lGDBQMzv

— Mark Gatiss (@Markgatiss) July 25, 2016

While we may not have the pleasure of Tom Hiddleston’s appearance in the show (as many a fan, myself included, speculated), we just might get introduced to the third Holmes brother. This seems likely, as one of the keywords released at SDCC was the name “Sherrinford.” As we know, Sherrinford is the name of the eldest Holmes brother in a fictional (in that it was not penned by ACD) Sherlockian biography. And we mustn’t forget Mycroft’s cryptic mention of “the other one” at the end of series three. The latest trailer also shows Sherlock looking sad and shocked as he gasps the words, “I love you” to the camera. Is he possibly talking to his long-lost brother, who may be locked up somewhere for either mental illness or addiction?

3.) The dying detective

Thus far in the BBC adaptation, we’ve seen Sherlock with facial hair all of twice. The first time, it was part of a disguise (and drawn on with eyeliner). The second time, Sherlock has been investigating (and participating in) a drug den and has let his hair grow disheveled. Sneak peeks of series four have shown Sherlock once again with scraggly facial hair, and looking rather unkempt. Is it a sign that he’s using again, or simply part of a disguise? A popular fan theory that seems likely to me is that we’ll see an adaptation of “The Dying Detective” in which Sherlock pretends that he’s contracted a terrible illness in order to force a confession out of someone. But knowing Gatiss and Moffat, it won’t be quite that simple.

4.) The return of Jim Moriarty

We can reveal that episode 3 of #Sherlock series 4 will be titled ‘The Final Problem’. pic.twitter.com/YDNTBoxoSw

— Sherlock (@Sherlock221B) December 9, 2016

While this seems rather obvious to me, and to a lot of fans, it could all be an elaborate red herring. So, take everything I say here with a grain of salt. There’s more than one finger pointing to the apparently inevitable comeback of Sherlock’s nemesis Moriarty. The Collectress and I waxed eloquently about several Mori-theories in 2015, and there are also some clues scattered throughout the trailer. Some of it may be flashback footage meant to lead us astray, but it seems rather certain that we will find out something more about Moriarty. Is he really dead? Did someone in the Holmes family create the mysterious footage to keep Sherlock from certain death? Is Mary (or was Mary) connected to the villain? Perhaps the greatest implication is the title of the third episode, “The Final Problem.” In the ACD canon, this is the story in which Moriarty and Sherlock take their deadly tumble at Reichenbach Falls.

Share your own theories with us on Twitter @nerdwrldprblms, and we’ll see you on New Year’s Day!

The game is on,

The Collected Mutineer