Sherlock fans should expect the next season to be kicked up a notch, at least according to the show's star.

Benedict Cumberbatch, who plays Sherlock Holmes in the series, spoke with (seen below) after San Diego Comic-Con about the upcoming fourth season featuring both the show's typical humor and also some real darkness.

"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," Cumberbatch explained. "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. It's fast, it's funny. It's got a lot of action, a lot of twists and turns. It's everything that Sherlock has been but evolved to a really exciting level."

Season 4 will see Sherlock back in London, as Watson (Martin Freeman) and Mary (Amanda Abbington) adjust to expecting a child.

"Sherlock series four-here we go again!" said executive producers Steven Moffat and Mark Gatiss in a previous statement. "Whatever else we do, wherever we all go, all roads lead back to Baker Street-and it always feels like coming home. Ghosts of the past are rising in the lives of Sherlock Holmes and John Watson bringing adventure, romance and terror in their wake. This is the story we've been telling from the beginning. A story about to reach its climax..."

Season 3 ended with a huge cliffhanger, with the villainous Moriarty (Andrew Scott) returning from presumed death. It remains to be seen how this will be resolved.

A specific premiere date for season 4 of Sherlock has not yet been announced, though it is generally expected to come out in early 2017.