Hyun-myung, Doo-yong, and Gun-woo decide to spend the night at their hidden spot by the pond to mark the end of their high school days and celebrate Sung-pil’s sister Kyung-mi’s birthday. As the night progresses and the party heats up, Gun-woo and Kyung-mi leave briefly to retrieve something from home, but they never return. The others set out to find them, only to discover Gun-woo’s damaged scooter and Kyung-mi’s lifeless body at the edge of town, with Gun-woo nowhere to be found. Four years later, Hyun-myung returns to town and reconnects with his old friends, eventually uncovering the truth about what happened that night.