Song-young and Song-mi are sisters who came all the way from Seoul to celebrate their mother’s birthday. While spending the happiest moment in the world, Yoo Jae-ma, a notorious serial killer on the loose drops in. However the girls and their mother find out the truth behind his murders.

A young girl is kidnapped by a serial killer. The serial killer uses manholes to kidnap and kill his victims. The young girl's older sister tries to save her before it's too late.