A decade after apocalyptic events, when civilisation has been destroyed and the human race diminished, an unnamed man and his son are travelling alone through America. They are aiming for the coast, not knowing what they will find there, but secure in the hope that it will give them the best chance to survive the endless, freezing winter.

It may sound like a dismal viewing experience: the barren landscape is burdened with ash, it is enduringly dark and grey (colour only comes in pre-apocalypse flashbacks), and there is constant danger of lawless, even cannibalistic bands. But the majesty of this film is in the power of the love between father and son, and in the unnerving realism of an apocalyptic horror. It is impossible to look away. Mortensen gives a stellar performance as always, but the real discovery of this film is Kodi Smit-McPhee - his maturity and passion are astounding. While the father is desperate to protect his son (with only a pistol, a shopping cart with bits of food, and the clothes on their back), the man is constantly learning from his son, and Smit-McPhee holds the screen with Mortensen wholly.