Touching the Void (2003)

Touching the void is a documentary-esque thriller that tells the story of two mountain climbers attempting to climb a mountain-face that has never been successfully climbed before. The film explains early on the 80% of accidents happen on the way back down, which is when everything seems to go wrong for these climbers. After a life-threatening accident, the two climbers struggle to make their way back down in the mountain in one piece, having to tackle a seemingly endless number of hurdles that are preventing them from getting to the bottom. Despite that you are always aware that the climbers survive, due to them narrating the story, you still find yourself worrying for their lives. It's impossible to tell what is going to happen next and you can't predict how the climbers are going find their way back to their camp at the foot of the mountain.