Paul is scavenging for supplies in a storehouse and then fleeing through deserted back alleys, with the pandemonium of an apocalyptic event in the background, sirens blaring, sounds of distant explosions, and people screaming. He seeks refuge in a secluded spot, cradling his two infant boys and reassuring them that everything will be okay. Fifteen years later, after a pandemic has wiped out most of the population and caused civilization to break down, Paul and his twin sons, Joseph and Thomas, live in a derelict farmhouse, eking out what livelihood they can during the day and sheltering from monstrous photophobic creatures at night.