"Sherlock" season 3 premiered as far back as 2014, but fans won't have to wait much longer as season 4 is officially premiering on New Year's Day in both the U.S. and the UK. The season will open up with the episode "The Six Thatchers" and will be followed by two more episodes, each one an hour and a half long.

Along with the announcement of the premiere date the "Sherlock" Twitter account posted a new trailer. This trailer further hints that this is going to be the darkest and most twisted season of the show thus far. It also focuses a lot on the villain Moriarty (Andrew Scott) who died during the season 2 finale.

This trailer showcases Sherlock (Benedict Cumberbatch) and Dr. Watson (Martin Freeman) being brought back to England despite being exiled during the season 3 finale. A line in the trailer states that they were brought back to deal with a problem, and Sherlock was needed to solve the issue as soon as possible.

In the trailer, Sherlock is also told that he should not treat these issues as a game, further implying his feud with Moriarty is still not over. The trailer then cuts to the new villain of the season, played by actor Toby Jones. Military personnel is also present throughout the trailer, indicating season 4 is going to be more violent than previous seasons.

"Ghosts of the past are rising in the lives of Sherlock Holmes and John Watson and terror and tragedy are looming. This is the story we've been telling from the beginning and it's about to reach its climax," explains co-creator and showrunner Steven Moffat in a report from The Nerdist.

It is highly speculated that Moriarty is indeed dead, but he had planned future events and may have been working with Toby Jones' character. It is also speculated he may have somehow faked his death and is indeed coming back.

"Sherlock" season 4 premieres on Jan. 1, 2017.