The fourth season of "Sherlock" has reportedly been pushed back to 2017. It was initially reported that the season will hit TV screens in 2016. 

The reason for the delay is Benedict Cumberbatch's alleged casting in the Marvel movie "Doctor Strange." The British actor is said to have been tapped to play the main character, Stephen Strange, and taping of the movie will reportedly commence next year.  

Moreover, the actor has a jampacked schedule. Thus, the new season of the series was pushed back so that the actor can accommodate all his other commitments. 

However, fans do not have to be sad as the series also planned a Christmas special slated for December 2015 to ease the anticipation of the fans. The plot for the Christmas special will be based on the mystery "The Adventure of the Blue Carbuncle." Meanwhile, the storyline for the fourth season is still undecided. 

Nonetheless, fans will be delighted with the news that the previous three seasons of the series will be available in DVD and Blu-ray sets soon. 

According to reports, the season 4 of "Sherlock" will be darker and more devastating than the previous seasons. Also, showrunner Steven Moffat previously said that the characters of the series will be taken to another place. The executive producer probably meant this metaphorically, but he assured that the crew behind the series has a lot of ideas for next season. Moffat also said that the season 4 will top the previous season of the series. 

Series co-creator Mark Gatiss told Radio Times that the production team behind the series wants the season 4 to be at least at par with season 3. He added that instead of introducing a new antagonist like Moriarty or Charles Magnussen, Gatiss revealed that they are looking for a story that is parallel to the previous season.