'Sherlock' may come to an end after the next series.
Benedict Cumberbatch as Sherlock
Steven Moffat, the executive producer of the BBC One show, doesn't think it'll be long before the crime drama will wrap up for good as he believes it'll be harder to secure lead stars Benedict Cumberbatch - who portrays the titular detective - and Martin Freeman, who plays his sidekick Doctor Watson, because they're so in-demand nowadays.
Speaking to the Daily Telegraph newspaper, Steven said: "I don't know how long we can keep it going.
"I'm personally willing but I'm hardly the main draw. I would be moderately surprised if this was the last time we ever made this show. But it absolutely could be ...
"We do have two film stars in the programme. They haven't needed to do these jobs for a very long time. They're coming back because they want to."
However, the 54-year-old screenwriter is surprised they've managed to get four series out of the drama already as he was convinced Benedict, 39, and Martin, 44, would quit once they became international stars.
He explained: "I'm amazed that we've got this far. I thought that once they had become extremely successful, we would only get to do one more series."
Meanwhile, Steven is adamant there are no plans to extend the amount of episodes in each series as he believes fans enjoy it far more when they're left hanging.
He said: "There's never going to come a time when we do a longer run, because this is what the series has become. It's an occasional treat where you get three movies."