Sherlock creators Steven Moffat and Mark Gatiss teased fans on the upcoming season 4 of the hit detective drama at an event on March 4, 2014.

Moffat and Gatiss reportedly provided clues on what is to come for Benedict Cumberbatch's Sherlock Holmes and Martin Freeman's John Watson characters.

According to The Hollywood Reporter, both creators said that Jim Moriarty, who was shown in the season 3 finale, will be featured in the new season. THR also reported that "the show is likely to see increased roles for female characters Molly Hooper (Louise Brealey) and Mrs. Hudson (Una Stubbs)."

Producers have already planned on what will be happening in season 4, but will have to work around the two actors' busy schedules to begin filming.

After a long wait of two years, Sherlock season 3 finally aired in January this year. The rumored air date for Sherlock season 4 is set to be for 2016, which will be another two years for avid Sherlock fans.

Gatiss recently told Metro: "There was suddenly a kind of outraged response that it might not be back until 2016 but that's precisely how long it always is. It's always two years! But we'd like to return soon, of course." He continued, "The idea of growing older with it would be great. But it is hard to get everyone back together, because they have become extremely famous -- except for us."

Sherlock is a British television crime drama with a contemporary update to Sir Arthur Conan Doyle's Sherlock Holmes detective stories. The show was created by Steven Moffat and Mark Gatiss, and stars Benedict Cumberbatch as Sherlock Holmes and Martin Freeman as Doctor John Watson. Six episodes have been produced so far. The first three episodes aired in 2010, and series 2 aired in 2012. Production for series 3 started in March 2013 before airing on Jan. 1, 2014.