The protagonist is a humble tally clerk in a supermarket chain. After the doomsday came, he found that the entire supermarket warehouse where he worked had become the only safe zone connecting the civilized world and the doomsday wasteland. The goods on the shelves take on different forms in the two worlds: they are ordinary goods in the civilized world, and they become top-level survival resources in the wasteland (such as cans become high-energy military rations, liquor becomes fuel, and batteries become energy cores).
