Sherlock Season 4 Air Date, Cast, Trailer & Update: Steven Moffat Confirmed the Release of Season 4

"Sherlock" fans are now celebrating as their favorite British drama series confirmed next season installment is coming next year. The contemporary version of Sir Arthur Conan Doyle's detective stories Season 4 is set to be aired in Jan. 2017.

Steven Moffat explained that "Sherlock" is quite delayed because of their busy schedules. However, he teased their supporters by saying that the first three scripts for Season 4 are now ready to be used.

The 54-year-old television writer also hinted that the upcoming season will be more about "chickens coming home to roost." "It is dark in some ways - obviously, it is great fun and a Sherlock Holmes romp and all that - but there is a sense of things coming back to bite you," he said.

"It is not a safe, sensible way to live. It is hilarious and exhilarating some days, but some days it is going to be bloody frightening." Also, he hinted that their show's followers should wait for some surprises that might come along "Sherlock" Season 4's return.

Meanwhile, during an interview for the crime drama television series' Christmas special, "The Abominable Bride," the program co-creator Mark Gatiss unveiled that they are planning to include Mary into the Sherlock-Watson duo.

"We deliberately set out to make it like the best times for the three of them as a new team, that they would really have a great time," the 49-year-old screenwriter said. To recall, Mary was seen as the "super-agent" in the third episode of "Sherlock" Season 3, "His Last Vow."

"And the special really does bridge that in so many ways," the actor added. "Even though Mary is very proactive and a huge part, it's a sort of breathing space between 'Vow' and the next one."

In the said episode, Mary permanently changed when her longtime secret, which was her being a super agent, was revealed. And as she exhibited her skills as an assassin, it looked like she's a perfect fit to be part of Sherlock and Watson's team-up.