'Sherlock' season 4 teaser photos, details and updates: new teasers feature the new villain and Mary and John's baby

BBC's crime drama, "Sherlock," is slated to release its fourth season by Jan. 2017, and while it gets nearer, the network released six new teaser photos to gain more hype for the upcoming season.

One of the main teaser highlights is the new villain of the show, Culverton Smith, who will be played by Toby Jones. He is already claimed as the darkest villain of the show yet, with executive producer Steven Moffat calling him the "purest evil."

Moffat previously teased his character saying, "He's the darkest villain we've had," adding that "There was always something charming and engaging about Moriarty. There was something fascinating and actually amoral, rather than immoral, about Charles Augustus Magnussen. This guy [Culverton Smith] is the purest evil."

In another teaser photo, Sherlock (Benedict Cumberbatch) is looking quite funnily at the baby that John Watson (Martin Freeman) is holding. Previous speculations about Mary (Amanda Abbington) dying in the fourth season due to childbirth are proven wrong, because she is also seen in the photo along with the baby, John, and Sherlock.

Freeman had just got back to reprise his John Watson role. However, Cumberbatch previously said that Freeman's busy career schedule might delay production for season 5, if ever the show does get a fifth season.

The future of "Sherlock" still hangs in the balance as Cumberbatch previously said during an interview that "it feels like the end of an era."

"It goes to a place where it will be pretty hard to follow on immediately. We never say never on the show," he said. "I'd love to revisit it, I'd love to keep revisiting it, I stand by that, but in the immediate future we all have things that we want to crack on with and we've made something very complete as it is, so I think we'll just wait and see. The idea of never playing him [Sherlock] again is really galling," he continued.

"Sherlock" season 4 premieres on Jan. 1, with its first episode titled "The Six Thatchers."