A young girl's family tries to rescue her from a monster living in the Han River; after her simple-minded son is tried and convicted for murder, a single mother, believing her son to be innocent, sets out to find the real killer; driven crazy by the incessant yapping of a noisy dog in a nearby apartment, a part-time college lecturer with an expectant wife eventually snaps and takes matters into his own hands, but soon his actions begin to snowball as the apartment building owner becomes increasingly determined to resolve the mounting complaints of missing pets.