A man recently released from prison is found brutally murdered. Tracing the murder back to a case from 14 years ago, the criminal investigation team consults Dong-soo, the detective who was in charge of the old case. Dong-soo instinctively senses that this recent murder is related to Yo-han, the son of the victim murdered 14 years ago.

Si-young is an executive assistant to Seung-jo, the head of a conglomerate. Si-young is ordered to follow every move of Mi-ho, Seung-jo!|s fiance. Mi-ho seems perfect in every way, but little by little suspicious traces of her past are uncovered. And he notices someone haunting her like a shadow.

Si-young and Dong-soo come across each other at one point while tracking down each of their targets. They discover the horrifying truth of Yo-han!|s and Mi-ho!|s past; the suspect of the past murder was Mi-ho!|s mother and the victim was Yo-han!|s father. The lives of Mi-ho and Yo-han have traveled in opposite directions, one towards a bright light and the other towards a dark shadow. While Mi-ho now lives a new life, Yo-han is still stuck in a miserable darkness.

Mysterious murders that go back to 14 years

What is the truth?