An unnamed father (Mortensen) and his young son (Smit-McPhee) struggle to survive after an unspecified apocalypse and make their way toward the coast for possible food, shelter, safety, or to potentially find other survivors of the cataclysmic events. Along the way, they encounter grave struggles and hardships across the barren landscapes, with scarce shelter and resources available to them, and having to avoid bands of cannibals and other desperate gangs looking to pillage valuables and food. Various flashback sequences occur where the Man remembers events prior to the catastrophe, many involving his deceased wife.