A middle-age couple visit a temple in Chuncheon where they spent their first night together 30 years prior. On the way, one of them cannot find their phone and hurries to find it. As the night unravels, they will come across an ex-lover, a friend, and a young couple who resemble them 30 years ago.
Su-hyeon, a teacher at a private art institute and Ji-young, a contract worker at a small network enterprise have been living together for 6 years. To his surprise, Su-hyeon finds out that Ji-young is late on her period. One evening, the couple heads to the new home of Ji-young's parents in Incheon. The housewarming party dissolves in ill humor when Ji-young's mother strongly urges the couple to get married. At the end of a long day, the couple tries to sleep. As Su-hyeon decides to reunite with his family he had been avoiding for some time, the couple sets off for Samcheok at the far end of the east coast.
Hyunjin, a test taker, moves into an old apartment. There are strange sounds from next door where a strange boy named Hyunggu lives. One day, Hyunggu and his mother are cruelly murdered.
A pawnbroker is found murdered in a remote town in a derelict building. Three people come under suspicion but all of them have perfect alibis and the investigation comes to a standstill. Almost fifteen years pass and the lead inspector decides to re-investigate.
Detective Kang gets involved with a drug business to pay the medical bill of his comatose wife. Min-woo confesses to Kang that he has killed his wife, who knows his past. Slowly, Kang realizes his wife's incident and Min-woo are connected.
