Fans of the immensely successful BBC series "Sherlock" are in for a treat. The network has confirmed that filming for the series has commenced and season 4 will air most probably in January 2016. Apart from the regular episodes for season 4, there will also be a single "Christmas special" feature episode that will air near the end of 2015.

Over the past three seasons, "Sherlock" has achieved near-cult status in the U.K. as well as in the U.S. Benedict Cumberbatch has, through the series, certainly managed to amass for himself an army of passionate fans, especially among the young female crowd. 

For the first two seasons, there was a substantial gap between the U.S. and U.K. premiere dates. The gap was shortened in the third season, and most probably the fourth season premiere will see a simultaneous release for the U.S. and U.K. television audiences. In the U.S., the show airs on PBS. 

Writer and executive producer Steven Moffat, in talking to Entertainment Weekly, stated that the creative team behind "Sherlock" was planning to take the series to a darker and more intriguing space in the next season. Fans can expect to see Watson as a father when the show returns. It would definitely be interesting to see how Sherlock, Mary, and John accommodate a new member in their lives. 

Hardcore fans of the series also speculate that another brother of Sherlock will be introduced really soon in the series. There has been quite a lot of talk about Tom Hiddleston, who starred as Loki in "Thor" and "Avengers," joining the cast of "Sherlock." However, nothing has been confirmed in this regard. 

During the BBC announcement for the fourth season, Moffat stated that there will definitely be a lot of other shockers in season 4 and that viewers can expect things that they would never have expected to happen.