Following the intriguing revelations at the end of the special “The Abominable Bride,” anticipation for Sherlock Season 4 is very high. A lot of it has to do with Season 4 being released in early 2017. Recently, details have emerged about the BBC hit series’ filming locations.

Express UK reports that “Sherlock” Season 4 may begin filming at Pinewood Studios in Wales, located on the borders of Cardiff at Wentloog. Some of the upcoming films like the “Assassin’s Creed,” “Alice Through the Looking Glass,” and “Me Before You” were also shot there, mentions Christian Today. The final two-part Harry Potter films were also filmed at Pinewood.

“Sherlock” which stars Benedict Cumberbatch as Arthur Conan Doyle’s famous consultant detective and Martin Freeman as his friend Dr. John Watson, has been previously shot in South Wales. The January 1 special “The Abominable Bride,” which also had a limited theatrical release, was shot in Bristol.

Express UK says that the Welsh government, which has a £30 million (around AU$60 million) media investment fund – may be providing financial assistance to the project. A BBC spokesperson, however, told Wales Online as quoted by Express UK, that “It’s too early to confirm filming details of the new series of Sherlock.”

Though no plot details have been announced yet, there are rumours that John’s wife Mary Morstan (Amanda Abbington) could die in Season 4. Actor Martin Freeman had said Mary could be killed off in line with Conan Doyle’s stories.

“While we play fast and loose with the original stories, we generally follow the trajectory of what Conan Doyle did,” Freeman had told The Telegraph. “So he [Watson] gets married and then Mary dies – so at some point presumably she’ll die.”

In Conan Doyle’s storyline, she died at an unspecified point between “The Final Problem” and “The Adventure of the Empty House,” and her passing is mentioned briefly by Holmes in the latter. Her death, if it is to occur, could be part of the “consequences” Steven Moffat said Season 4 will explore, in an interview to Entertainment Weekly.

Another EW article quotes “Sherlock” writer-producer and actor Mark Gatiss saying that Season 4 will have a dark climax. “We’re going to try to take it somewhere we’ve never been before — and I don’t mean outer space,” he said. “It will be challenging place to go. We always start with a re-introduction that builds toward a darker climax – we might just be going darker [from the outset]. We got a very, very good set of ideas,” said Gatiss.

What Moffat said, in the same article, falls in line with the possibility of something tragic happening at the end of “Sherlock” Season 4. “We have a plan to top it [Season 3]. And I do think our plan is devastating. We’ve practically reduced our cast to tears telling them the plan … we’re probably more excited that we’ve ever been about Sherlock,” said Moffat.

More details are expected to emerge as production begins for “Sherlock” Season 4 in spring this year.