BBC One is still mum about any information pertaining to "Sherlock" season 4, but fans are still speculating about the characters' fate when the series returns sometime in 2017. 

In March, the ever-secretive series co-creator Steven Moffat told the Entertainment Weekly that they still have not started writing the scripts for "Sherlock" season 4, but he hinted that the season will dwell on "consequences." He also said that the fourth season of the popular British crime drama will be more serialized compared to the first three seasons, and it will be filled with a lot of mysteries. 

But early last month, Moffat told the media personalities present during the BAFTA winners press conference that they will start filming the series in spring next year. It means that "Sherlock" fans will have to wait a little more before the fourth season of the series premieres, presumably in 2017. 

But fans don't have to wait that long to see actors Benedict Cumberbatch and Martin Freeman reprise their roles as Detective Sherlock Holmes and his trusted friend Dr. John Watson since a stand-alone Christmas episode will be aired later this year. The one-episode special will run for 90 minutes, and it will have its own plot that is separate from the regular seasons.

Still, fans are already looking forward to seeing what will happen to the characters. As avid viewers will recall, by the end of season 3, Dr. Watson finally wed Mary Morstan and the two were expecting their first child together. But readers of the novels written by Sir Arthur Conan Doyle know that Mary will eventually die for an unknown reason, prompting Watson to return to his former house in Baker Street. 

While the exact release date of "Sherlock" season 4 is still unrevealed, Moffat and co-creator Mark Gatiss already confirmed that they have already conceptualized the plot for the show until season 5.