'Sherlock' season 4 news and updates: Cast, crew continue filming amid heavy downpour; Sian Brooke to portray Sherlock's new ally

The fourth season of "Sherlock" is one of the most-awaited shows set to premiere next year, and among new faces and storylines, fans will see a new villain to bring more trouble when the series returns.

The show recently wrapped up its shoot in Morocco, and now the whole cast and crew are headed to London to continue filming. Sherlock Holmes' portrayer, Benedict Cumberbatch was spotted with Sian Brooke as they braved a downpour while shooting in London, and according to reports, Brooke's character might be one of the detective's allies. Cumberbatch appeared to be holding a piece of paper which might be a script or a prop from the show.

As noted by The Daily Mail, most people in the U.K. prefer to stay indoors due to torrential rains, but the production team and cast continued shooting scenes despite the bad weather. Behind-the-scene photos show the cast and crew soaked because of the heavy rain, but fans were still present to support their favorite stars. Amanda Abbington expressed her gratitude via Twitter to fans who were there saying: "A huge thank you to everyone who came down to set today. A pleasure meeting you all. Massive love and hope you got home safe."

"Dark" is possibly the next season's main theme, as previously hinted by Steven Moffat. "[Season four] is going to be... I suppose you'd say... consequences," he said. "It's consequences. Chickens come to roost. It's dark in some ways - obviously it's great fun and a Sherlock Holmes romp and all that - but there's a sense of things coming back to bite you."

"It's going to be more of an emotional upheaval. Hopefully enjoyable and fun, all the things Sherlock must always be. It will be tough at times," Moffat added.

"Sherlock" season 4 is expected to premiere in January 2017.