Sir Arthur Conan Doyle’s “consulting detective” Sherlock is already confirmed for his modern TV return in a one-off (possibly Christmas) special; however, with roughly a full year before Benedict Cumberbatch and Martin Freeman return as Sherlock Holmes and John Watson, respectively, fans are already eager for details on season 4 of the acclaimed BBC miniseries. An official timeline regarding when exactly showrunner Steven Moffat plans to shoot season 4 has yet to be announced by the network but co-creator (and Mycroft Holmes actor) Mark Gatiss has previously indicated that filming on the new episodes will take place later in 2015 – and air sometime after the solo special.

Of course, this means that Sherlock season 4 will not debut until 2016, so fans have a lengthy wait ahead of them for the ongoing adventures of Sherlock in modern London (those who are interested in the ongoing adventures of Sherlock in New York City can always watch Elementary on CBS). While Moffat is already hard at work scripting Doctor Who season 9, in a recent interview Gatiss claims that, at the very least, the Sherlock team knows where the story will go in season 4 – and it won’t be pretty.

Speaking with Radio Times on the subject of Sherlock season 4, the co-creator stated: “You can always expect tragedy as well as adventure, that’s just how it goes.

Sherlock Season 4 Premiere Date Sherlock Co Creator on Tragedy & Moriarty in Season 4


Without a doubt, Sherlock is no stranger to adventure (especially considering the modern show has already seen its titular detective investigating a number of strange cases) but viewers are likely to hone in on Gatiss’ promise of “tragedy.” Holmes and Watson have faced their fair share of troubles throughout seasons 1-3 (as well as before) but few events depicted in the series have left a particularly permanent impact on the pair. Watson, especially has endured torturous experiences: As a war veteran and best friend to an arrogant genius, Freeman’s character has fought depression, post-traumatic stress, and nearly a year’s worth of grief (believing Holmes to have died), but still managed to find happiness with Mary Morstan (played by Freeman’s real-life wife Amanda Abbington).

Yet, for season 4, the series’ co-creator seems to be hinting at something Earth-shattering. Longtime fans of Doyle’s work will, very likely, assume that “tragedy” corresponds to the death of a key supporting character (which we will not spoil here) but Gatiss also makes it clear that even though a key player dies in the books doesn’t necessarily mean the show will repeat that same arc:

“Just because it’s in the stories doesn’t mean it’ll happen in the series because there’s an awful lot of changes and an awful lot of places to go and things to do. It should be clear by now that while, of course, Doyle is our absolute god, we have gone quite a long way away as well – we’ve introduced Sherlock and Mycroft’s parents [for instance], I don’t think they’ve ever been seen in any adaptation – so there are lots of surprises to come.”

Previously, Gatiss had already indicated that season 4 “will take Sherlock and John Watson into deeper and darker water than ever before.” Coupled with the co-creator’s new comments, fans can assume that “deeper and darker water” will come with some major (tragic) consequences.

Watson Sherlock Sherlock Co Creator on Tragedy & Moriarty in Season 4


So what darkness awaits the consulting detective and his best friend in forthcoming episodes? In a separate interview with Radio Times, Gatiss indicated that the one-off (likely holiday) special will “completely” solve the mystery of Jim Moriarty’s message from beyond the grave from the season 3 finale. For those who may have forgotten, following the events of the “The Last Vow” (which borrowed elements from the original Doyle stories: His Last Bow, The Adventure of Charles Augustus Milverton, and The Man with the Twisted Lip), Sherlock’s iconic antagonist suddenly reappears – broadcast on TVs across London with the message “Did you miss me?”

Addressing the return of Moriarty, Gatiss refused to comment on whether the villain is truly alive or simply screwing with Sherlock in an after-life video, stating: “Well, it’s very hard to put a lid on Andrew Scott [the actor who portrays Moriarty].

Moriarty’s presumed suicide at the end of the season 2 finale, “The Reichenbach Fall”, was divisive. Some viewers were glad to be relieved of Scott’s controversial take on the iconic evildoer while others began developing complicated theories to explain how Moriarty might, like Sherlock, have managed to fake his death.

Sherlock Season 4 Moriarty Miss Me Sherlock Co Creator on Tragedy & Moriarty in Season 4


Still, just because Gatiss indicates that the 2015 special will completely solve the mystery of Moriarty’s video message, there’s no direct indication that Scott will have a major part in the episode (or the series going forward). It’s safe to assume that by the end of the episode viewers will know if the malevolent schemer is truly dead but could the video message actually be the first step in Holmes and Watson’s journey into those darker waters – one that leads them to an even more dangerous threat?

Ever since Cumberbatch became an A-list film commodity, with Freeman not too far behind on the Hollywood guest list, scheduling has become the biggest challenge of Sherlock season productions. As indicated, the pair is confirmed for filming the Sherlock special in January 2015 but BBC has yet to reveal an official start date for production on the subsequent three episodes. Still, despite some scheduling hurdles, the network is planning on shooting the bulk of Sherlock season 4 late in 2015 – though that plan could shift dramatically if their star accepts the lead role in Marvel’s Doctor Strange.

Benedict Cumberbatch as Sherlock Sherlock Co Creator on Tragedy & Moriarty in Season 4


Nevertheless, we know that Cumberbatch and Freeman, not to mention Gatiss and Moffat, enjoy coming together for new Sherlock installments – even mapping out where season five could go. The show is a labor of love, even if scheduling conflicts arise (again), there’s little doubt that viewers will get to relish in the “adventure” and “tragedy” of Sherlock season 4 – eventually.

Next: 5 Best ‘Sherlock’ Moments (So Far)

Sherlock season 4 does not have a confirmed release date. We’ll update you as we know more.

Follow me on Twitter @benkendrick for updates on Sherlock as well as future movie, TV, and gaming news.

Sources: Radio Times (Link 1) & Radio Times (Link 2) [via Variety]