Moo-Sung (Kim Hee-Won) works as a prison officer. He is divorced and raises his young son alone. He doesn't have a great relationship with his son and he isn't a great employee either. One day, he accompanies female prisoner Yoon-Hee (Kim Sun-Kyung) on leave from the prison. When they get to the subway station, Yoon-Hee runs away. Moo-Sung must bring her back to prison by 10 PM.