Sherlock will evolve to a really exciting level in "Sherlock" season 4.

Last month, fans caught a glimpse of some set photos showing Sherlock with his bloodhound in tow. Just recently, the actor behind Sherlock, Benedict Cumberbatch, revealed some interesting details about the upcoming series that will surely make its fans anticipate it all the more.

In his interview with Comicbook.com, the actor revealed that the new series is going to be fast, funny and full of action. It also offers a lot of twists and turns.

"It's everything that Sherlock has been but evolved to a really exciting level," said Cumberbatch.

The actor went on to tease that season 4 will be a lot like darkness and humor rolled into one.

Meanwhile, fans who are worried about the conflicts among its characters in the previous season do not need to worry any longer, as Cumberbatch reassured them that Sherlock's relationship with his friends and family will remain strong and deep in the upcoming installment.

"It's difficult, this one, because obviously, you have to manage expectations like I was saying in the panel just now. At the same time, I want to share the joys of what this has got coming for fans. It's so irritating because you can only talk in broad bracket terms. It's very dark. It's the same strain of trademark humor, the relationships are strong and deep and really complexified by what goes on," he said.

As for Moriarty's return, the message he sent to Sherlock in season 3 could mean he's coming back next season.

"Sherlock" season 4 is set to premiere on New Year's Day in the United Kingdom.