A rumor circulates about people disappearing after they party all night on Club Day, then taking the first train home. Ryung and Ji Seok get on the first train to find out whether the rumor is true. During their train ride, they run into a suspicious petty thief and the truth about the first train rumor comes to light. Meanwhile, Ryung finally meets the Subway Ghost a month after joining the Subway Police. (Source: Viu)