'Sherlock' will near 'climax' in Season 4

LONDON, April 7 (UPI) -- Sherlock fans can expect Season 4 to bring the series much closer to completion.

Series creator Steven Moffat teased the new season in a statement to news outlets following word filming is underway for Season 4 in London.

"Sherlock series four -- here we go again! Whatever else we do, wherever we all go, all roads lead back to Baker Street, and it always feels like coming home," Moffat said.

"Ghosts of the past are rising in the lives of Sherlock Holmes [Benedict Cumberbatch] and John Watson [Martin Freeman] and terror and tragedy are looming," he revealed. "This is the story we've been telling from the beginning and it's about to reach its climax."

Moffat's comments immediately caused speculation the BBC series is coming to a close, although the series creator has previously alluded to future seasons. He described Season 4 as "intense" in an interview with Entertainment Weekly last March.

"[Season 4 will leave fans] desperate for series 5," Moffat said. "We're certainly going to put them through the mill. 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."

"The reason we still have Benedict and Martin is we still give them acting challenges," he added. "They don't need the money ... We think really carefully about giving them something to play because they're both amazing actors."

Sherlock follows Holmes and Watson as they solve mysteries in contemporary London and is expected to return in early 2017. Season 4 will also see Watson and wife Mary (Amanda Abbington) prepare to welcome their first child.