EXCLUSIVE: 'Sherlock' Boss on Emotional Season 4: 'There Are Some Proper Shocks This Time Around'


Last we saw the Sherlock crew one year ago, things were a bit off-kilter for the characters -- due largely to the Christmas special’s Victorian-era setting and Moriarty’s mysterious (and presumed) resurrection. Now, with the debut of the anticipated fourth season mere days away, it’s back to business for the famous detective.

“It’s nice to go into the real story,” showrunner Steven Moffat tells ET. “One year ago with the Christmas special, we took a sidestep in the narrative. We’re finally getting back to the story we’re telling and that’s exciting.”

Moffat and company -- including star Benedict Cumberbatch, who plays the title character Sherlock Holmes -- have spent the past year warning loyal Sherlockians that the upcoming three episodes will be darker and more emotional. At Comic-Con this past July, Cumberbatch noted “there are quite a few tears.”

RELATED: Benedict Cumberbatch Teases 'Sherlock's' Most 'Ambitious' Season Ever

When asked to elaborate further on the season’s decidedly more dramatic tone, Moffat promised that the dry comedy and witty banter that has become one of the show’s most beloved traits still remains.

“I suppose it is darker,” he began. “However I’m worried that both the trailer and the interviews we all give sort of caricature that a bit. It’s still the same show. There’s still humor there, there’s still all the fun there. You aren’t expecting Chekhov. But yes, it gets as dark as it can really get.”

One interesting development that will shake up the dynamic between Sherlock and John Watson (Martin Freeman) is the arrival of baby Watson.

“I’m not going to go into the details of what we do about that. I would say that the observation that Sherlock Holmes tends to do things well, especially when it comes to his friends,” Moffat hinted. “He’s something of a d*ck, but he’s not a terrible man or anything -- he behaves himself, particularly around his friends and he does things subtly. Underneath it all, there is a bane of human kindness there.”

PHOTOS: Go Inside ET's Action Hero Photo Booth at Comic-Con

“In terms of the baby, there’s a tremendous paranoia about if you [make this life change] in television land, as if somehow the moment you have children you never do anything else,” he said with a laugh. “It’s not like we stop having adventures just because we’ve got a baby. You don’t! Sherlock’s reputation is far worse than it actually is.”

As for how fans should expect to feel after the three 90-minute episodes are over, Moffat offered this promise.

“I think it’s a very good ride,” he said. “If we manage to keep our secrets, there are some proper shocks this time around. There are some knock-out-of-your-chair moments. Lock yourselves away from all spoilers because it’s worth it.”

premieres Sunday, Jan. 1 at 9 p.m. ET/PT as part of Masterpiece Mystery! on PBS.