'Sherlock' Season 4 Air Date, Spoilers, News & Update: What's In Store For Sherlock Holmes? Everything That We Need To Know!

"Sherlock" Season 4 is already set to return with the first episode titled 'The Six Thatchers.' Its first trailer has just been revealed and would tell more of what to expect once the season kicks in.

It is speculated that the first episode of "Sherlock" Season 4 is most likely to follow on the story line from Sir Arthur Conan Doyle's short story. This is in reference to the story titled 'The Adventure of the Six Napoleons.'

"Sherlock" Season 4 returns with Detective Holmes (Benedict Cumberbatch) teaming up with John Watson (Martin Freeman). This season also sees Mary and John expecting their first child. It is expected that the upcoming season is set to be challenging for Sherlock and the Watson's.

The new trailer for "Sherlock" Season 4 is seen to be darker than the rest of the seasons. This also has a different feel since it is narrated by the new villain, Culverton Smith (Toby Jones). There seems to be more intensity in the upcoming season.

It has already been reported that Culverton Smith is the darkest villain that will challenge Sherlock in "Sherlock" Season 4. His rotten soul manifests in the things that he may do to make the detective's job difficult. The season has also been reported to be the darkest ever.

Meanwhile, "Sherlock" Season 4 will have three episodes and will have Moriarty's return. It seems that Sherlock needs to be quick since there is already more than one villain that may challenge him  in the upcoming season.

Fans have been longing to see what "Sherlock" Season 4 has to offer. The season will have more twists to the story and challenges to the characters. Sherlock is set to work harder this time once the upcoming season returns.

The trailer is out and gives a clearer picture to what "Sherlock" Season 4 is about. The series returns on January 1, 2017.