Jae-gu and Soon-young run a car repair company on a country road. Their livelihood is threatened by competition from a large car repair company in a nearby town. One day, a sudden business comes to them. Because of nails dropped by a truck entering or leaving a nearby construction site, a passing car has a flat tire. Jae-gu, who finally has some income, has an idea. He spreads nails on the nearby road at night and increases the repair fee. He wants to make a fortune from this, but it triggers a series of unpredictable accidents...