A VERY CHILLING FINALE

Dead bodies, a demonic sheriff, tons of snow – Fortitude promises...

The temperature in the Norwegian town of Longyearbyen is -25˚C, and Dennis Quaid is rolling around on the ice with his torso exposed. The actor, 64, is filming one of the most important scenes in the third and final series of Sky’s Arctic thriller Fortitude and is determined to do it perfectly, even if it means several takes and a serious risk of frostbite.

‘Conditions are genuinely dangerous out there,’ says the show’s creator Simon Donald. ‘But Dennis wanted to get it right, he wanted to be utterly convincing as a man who’s lost everything and is in a drunken death spiral. He just went for it and it was incredible.’

Those who have been glued to the first two series will know that Dennis, star of films such as Far From Heaven and The Day After Tomorrow, plays Michael Lennox, a fisherman agonising over the death of his wife Freya in Fortitude, the fictional town at the heart of the show. The story so far has seen the town’s inhabitants fighting for survival after an infestation of ancient wasps, which had been preserved in the permafrost. The wasps infected humans, turning them into zombie-style killers.

The death toll has been high, with characters played by a host of bigname actors – including Sofie Grabol, Christopher Eccleston, Michael Gambon and Stanley Tucci – meeting grisly ends. But in this final series, the central figures, including Michael and murderous sheriff Dan Anderssen, battle on.

‘Michael’s utterly miserable,’ says Dennis. ‘It was important to show him at a very low ebb. But the cold? I love it here. This is an Arctic western with the emphasis on the word “Arctic”.’

While Michael is taking potshots at his neighbours, Sheriff Dan, played by Richard Dormer is acting more strangely than ever. ‘He’s addicted to every substance on the planet and wants to communicate with the people he’s killed,’ says Richard. ‘Which totals nine, by the way – and counting.’

And the cast and crew faced their own terrors while filming. Wardens with shotguns were on patrol in case one of Svalbard’s 3,500 polar bears turned up. Crew members got frostbite. And Richard had ice on his beard 30 seconds after stepping out of his trailer.

‘It was a noble effort to keep going,’ says producer Andrew Wood. ‘The Norwegians were amazed we were there and said, “We’ve never had a big drama series come this far north.” We realised, during filming, why they hadn’t...’

Tim Oglethorpe Fortitude, Thur, 9pm, Sky Atlantic.

Dennis Quaid as Michael Lennox