It's been two years since fans were treated to a new episode of "Sherlock." With "Sherlock" Season 4 release date on its way, fans couldn't help but grow even more excited to reunite with the awesome duo of Benedict Cumberbatch and Martin Freeman. Here's everything you need to know about the series.

"Sherlock" Season 4 release date

"Sherlock" Season 4 will premiere on Jan. 1, 2017 on BBC. This is close to a statement made by Freeman before, in which he said that the series might come back sometime in December.

"Sherlock" Season 4 is the last?

Amidst the excitement surrounding the return of Cumberbatch and Freeman as Sherlock and Dr. Watson, there are also rumors that the fourth season will be the show's last and final run. According to TVLine, the "Doctor Strange" actor told GQ that "Sherlock" Season 4 "feels like the end of an era, to be honest."

He also said that the story "goes to a place where it will be pretty hard to follow on immediately." Moreover, Cumberbatch said that while he would never say never to the show he feels as though they have made something "very complete as it is."

Both Cumberbatch and Freeman are becoming busier with movie schedules. Cumberbatch just recently made his debut as Stephen Strange in Marvel's "Doctor Strange." Freeman is also part of the Marvel Cinematic Universe as Everett Ross, having appeared in "Captain America: Civil War."

"Sherlock" Season 4 villain

The upcoming villain is Culverton Smith, played by Toby Jones. The character is said to be the darkest villain the show has ever had, even surpassing previous bad guys such as Moriarty and Charles August Magnussen.

"He's the darkest villain we've had. There was always something charming and engaging about Moriarty. There was something fascinating and actually amoral, rather than immoral, about Charles Augustus Magnussen. This guy is the purest evil," executive producer Steven Moffat said, as quoted by The Independent.

The show will have an overall darker and more emotional tone. However, the birth of Dr. Watson and Mary's child is expected to bring some light into the show. Fans can already imagine how goofy an uncle Sherlock is going to be.