Ji-yeon, a tollgate ticket girl, is frightened by a mysterious black car, which pays a bloodstained ticket 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. Afterwards, a murder 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.

While investigating the school files, the frightened teacher Mrs. Park startles and calls the young teacher Eun-young Hur, telling her that the deceased Jin-ju Jang is back. The line dies and Mrs. Park is attacked and killed by a ghost. On the next morning, the teenager Jae-yi Yoon waits for her friend Ji-oh Lim, who has the ability to call the spirits, and they begin a close friendship. The abusive and aggressive Mr. Oh, a.k.a. Mad Dog, is the substitute of Mrs. Park and prohibits Ji-oh to paint and compares the performances of the pretty So-young Park and the weird Jung-sook Kim, raising a barrier between the two former friends. Miss Hur misses her former friend Jin-ju, who committed suicide, and while trying to contact her, she discloses a dark secret about the past of her friend and Mrs. Park.