The growing Hollywood success of Sherlock stars Benedict Cumberbatch and Martin Freeman could mean that the next series, which begins on Sunday night, is the last to be filmed.
Mark Gatiss, the co-creator of the BBC1 hit drama, said that while everybody involved was keen to record more episodes, the difficulty of scheduling the actors’ time was one of a number of factors meaning that future seasons were in doubt.
“We would love to do more, but we are not lying, we absolutely don’t know,” Gatiss told journalists and fans at a screening of the first episode of the new series. “It’s up to all kinds of factors, scheduling. Willingness to do it is all here, but we are just not sure.”
Cumberbatch played the hero in Marvel’s Doctor Strange earlier this year, and the character is slated to appear in at least two more films in the Marvel superhero series, Thor: Ragnorok and Avengers: Infinity War. Freeman has also become a global star since being cast in the first series in 2010, having played Bilbo Baggins in The Hobbit films.
Gatiss and co-creator Steven Moffat also have other commitments, including their work on Doctor Who, of which Moffat is the current showrunner.
Speaking at the screening, Cumberbatch suggested Sherlock would go through more of an emotional evolution than in previous series, becoming “less of a dick” in the process.
“He’s becoming slightly more, in a very clear way, responsible for his actions. I think he understands that it’s a slow, slow process that began with the very first instance when he met John [Watson], when you needed [that] missing part.”
“That friendship, that partnership in crime, that has been a humanising element all the way through all three series. I think he’s very much becoming more of a human being.”
He joked that show’s strapline should be: “Sherlock, coming back to you on BBC1 as slightly less of a dick, starring slightly-less-of-a-dick Benedict Cumberbatch.”
Freeman, meanwhile, said Watson would appear this time with more “shades of grey”. Offering up something of an explanation, Moffat added: “Dr Watson becomes slightly more of a dick.”
To complicate the picture, it emerged that Freeman has recently separated from his partner, Amanda Abbington who plays Watson’s wife, Mary, in the programme.
Sherlock has had his exile for murder abruptly curtailed after messages from vanquished foe Moriarty appear across TV screens, advertising hoardings, and social media, seemingly from beyond the grave. The series, which also stars Toby Jones as new nemesis Culverton Smith, has been billed as the darkest yet.
The team behind Sherlock have been at pains to avoid spoilers for the latest series, which begins where the special episode last January left off with the first instalment, Six Thatchers.
The first episode is loosely based on the original Arthur Conan Doyle story The Six Napoleons and sees busts of Margaret Thatcher smashed in search of important clues. Gatiss, who has said he based his performance as Sherlock’s brother, Mycroft, on Labour’s Peter Mandelson, said the choice of the former Conservative prime minister was not particularly political, but rather an updating of the story to the modern era where Sherlock is set.
“It’s a simple equivalence: we’ve modernised it. And with this one, we needed someone who was iconic ... she’s become like Napoleon.”
Moffat also revealed that an uncooperative bloodhound had led to a hasty rewrite during filming. “The big challenge was that beautiful dog,” he said. “It didn’t move. That was an immobile dog. Me and Mark [Gatiss] wrote that one [scene] on the street to account for the fact it wouldn’t bloody move.”
Gatiss added: “Having had years of terrible experience with animals, the people who tell you they train animals are liars. I imagine giraffes and all kinds of things, but it’s a dog, we basically got there with this bloodhound and she … it wouldn’t do a thing.”
Last year’s New Year’s Day episode of Sherlock, in which Holmes and Watson were transported to the Victorian setting of Doyle’s original books, was one of the most watched programmes of 2016, with 11.6 million viewers.
It was shown in cinemas around the world, and the last episode of the new series, The Final Problem, will also be screened in the UK and Ireland at the same time as it is broadcast on TV.