The protagonist is an unnamed, destitute vagabond who wanders from village to village selling small rattraps crafted from scrap wire. Because his trade is unprofitable, he resorts to both begging and petty thievery to keep body and soul together. His clothes are in tatters, his cheeks sunken, and hunger gleams in his eyes. Trudging along lonely roads, he spends his hours in solitary, bitter rumination.
One gloomy day, he is struck by an amusing philosophical epiphany: the whole world with its lands, seas, cities, and villages is nothing but a giant rattrap. It exists solely to set baits for people. Just as a small trap offers cheese and pork, the world offers riches, joys, shelter, food, heat, and clothing. As soon as anyone yields to temptation and touches the bait, the trap snaps shut, closing in on them forever.