A supernatural story about a mystic events occurring on the train, which had the route similar to the train which crashed many years ago.

To fight for custody of his daughter who loves playing the piano, a steel factory worker decides to forge a piano from scratch.

A struggling musician takes a job teaching music to middle school children in a rural mining town.

Unlike Gi-hoon, who is happy running a noodle shop with his mother in their hometown, Ji-eun distances herself from her family due to her ambition to succeed as an idol singer. The siblings, who have been hurting each other more than showing love, find their conflict deepening with the news of their mother's Alzheimer's, whom they thought would stay young forever.

Detective Jung-soo faces the victims of brutal murders who were killed for no reason and this makes him outraged. During the investigation, he meets Ji-hyun who is the only survivor and marries her, but they cannot escape from her tragic past. One day, Jung-soo's partner, So-young, arrives at the crime scene where she finds Jung-soo crying out in sorrow with his wife and daughter in his arms who are found viciously murdered after they went missing. But as the police and the law let the suspect go because for lack of evidence, Jung-soo decides to take vengeance himself on those unpunished killers and the cruel world.