This is a masterclass in survival and determination, filmed and acted so well you feel as if you are right there. The suffering chills into your bones and you marvel at the dogged willpower to stay alive. Filming against a constant background of blinding white takes great skill. Every frame shows care in composition and balance, with attention to visual detail. Every strength-sapping crunching step keeps the tension achingly tight. Truly an experience. Actor Mads Mikkelsen deserves a medal for his portrayal of human indomitability.