Writer Tim Foley said: “We’re picking up with Adam and Anne many years after the last story. They both have their separate lives, but Anne needs Adam’s help one last time. There’s an unusual property that’s key to the future of Department 7.

“It’s absolutely about the relationship between Anne and Adam. Louise and John Dorney are phenomenal together. I remember one brief exchange where they’re discussing what fish and chips to get, and even there they are electric – there’s an ease and a familiarity in the way they bounce off each other. That chemistry is key.”

Producer David Richardson said: “Working on three box sets of The Omega Factor was one of my favourite gigs at Big Finish, and so when executive producers Jason Haigh-Ellery and Nicholas Briggs asked for a special one off ‘audio movie’ for Halloween 2023, I couldn’t resist the prospect of returning to the characters of Anne and Adam.

“Tim is just a genius. I asked him to pitch a storyline and he came up with the most audacious concept – the only house that isn’t haunted. But the reason why it isn’t haunted is the scariest reason of all. His script is immaculate and rich and terrifying and perfect. We all loved it.”

Actor Louise Jameson said: “The Omega Factor is about scientists investigating the paranormal. It's kind of The X Files before its time. And The House That Wasn't Haunted is fantastic because it's a stand-alone story.

“It's quite a scary one. It taps into all those childhood fears of darkness and noises and feeling unsupported; all those things that most people suffered at some point.

“We've all been to those big old mansions where you suddenly feel cold for no reason. Where does that come from? Not just the thickness of the walls...”

John Dorney and Louise Jameson

John Dorney, Philip Hurd-Wood, Louise Jameson, Selina Cadell, Barnaby Kay, Reice Weathers