Train: 1x2

Episode 2

Do Won confesses to Seo Kyung that his father was the one who killed Seo Kyung’s dad 12 years ago. Seo Kyung feels shocked and betrayed. Meanwhile, Do Won chases the suspect of the Mukyeong Station Serial Murders, and Seo Kyung discovers her mother’s stolen jewellery from 12 years ago on the recently discovered corpses.