The world is in ruins after some apocalyptic event. A father and his son are walking towards the coast in an attempt to head south to escape the increasingly cold, endless winter. Along the way they have to avoid gangs forced into cannibalism. Their only weapon is a pistol with 2 shots. The father has dreams about his wife, who committed suicide before the story begins. At one point they find an intact bomb shelter filled with food and supplies. Rather than remain in this sanctuary, they continue on because they have not yet reached the coast. The only named character they encounter in the entire book is an old man who says his name is Ely. Ely is harmless and alone and they share a meal and talk for a bit. They find out Ely is not his real name and he created this false name in order to keep from being found by other refugees. They eventually part ways. The whole journey is a struggle to survive in a world no longer capable of sustaining life. They almost lose this struggle when a thief makes off with all their worldly possessions, and the Father nearly loses his struggle to hold on to his humanity in taking those possessions back. The boy is all that keeps him barely human. The boy is his warrant, in his own words. In the end, they reach the coast but find it is no different, no better than the place they left behind. The father finally succumbs to the illness that has plagued him from the beginning, dying and leaving the boy alone. But he is not alone for long before another finds him, another man holding on to his humanity - only he's been a little more successful because he had help. Now the boy has a family.
