Ji-yeon, a tollgate ticket girl, is frightened by a mysterious black car, which hands over a bloodstained ticket as a fee at midnight. Her fear deepens after her colleague, Jong-sook, tells her that 12 years earlier a prisoner transport vehicle caused a traffic accident wherein all the prisoners involved died – and some of the corpses disappeared. Since then, a murder has occurred near the tollgate on February 29th, every four years. Soon, odd events become increasingly frequent, usually involving a doppelganger of Ji-yeon. When Jong-sook is killed on the fateful February 29th, Ji-yeon – with the help of two detectives – starts looking into matters herself.