A tollgate ticket girl finds herself connected to a series of murders occurring on February 29th.

In 1976 on a remote island, schoolteacher Eun-young wants to take her students on a field trip to a cookie factory in Seoul. Even though the parents don't like the idea, Eun-young succeeds in taking them. But once they arrive in the complicated city, students become fascinated with high-tech bicycles and get lost.