Bear Grylls is used to tackling the world's toughest environments and facing wild terrain and animals, but now he's confronted by a new type of challenge - Hollywood actor and comedian Will Ferrell.
Will joins Bear for a special two-day survival mission in the Arctic Circle. He has no clue what to expect, and is more used to helicopters taking him to film premieres. But there's no red carpet waiting this time; he endures a terrifying descent with Bear as they abseil over 150 feet into an icy, rock-strewn gorge in northern Sweden.
As well as for overcoming the freezing temperatures and treacherous landscape, Bear's endurance is put to new use as he leads novice Will through the mission, while the actor offers his own offbeat approach - and comic rather than survival skills - on their journey.
It's a heart-stopping ride for Will. He has to battle the extreme cold and deep snow while Bear cooks up frozen deer eyeballs. Can Will handle the challenge?