Private Investigator Yoon San and his partner Yong Goo-hyung are hired to follow the brother of their client, who has been acting mysterious the last few weeks. The answers they find may not be what they expect.
An old police friends asks Yoon San to look into the case of her newly-deceased father's encrypted will. In investigating her father's past, he finds startling links to his own.
The team gets a call from a blind woman who thinks that her brother has been wrongfully convicted of murders to which he has admitted committing. The case unfurls rapidly, and both San and Gyeo Wool just might be connected.
The same day that Goo Hyung receives an invitation to a class reunion, a former classmate shows up at his door. She wants the gang to solve an old buried mystery, one that could explain some of Goo Hyung's past.
Dr. Hwang's sister appears to be possessed by a spirit. Yoon San spots a mysterious man following him. The team uncovers darkness from Dr. Hwang's past.
Yoon San can't help but act emotionally in his efforts to save Yoo Jin. His decisions lead to the unthinkable, and Goo Hyung is caught in the crossfire. Gyeo Wool is left out of the action.
Yoon San gets himself and Yoo Jin to rural safety, but that doesn't stop his friends and his foes from continuing to look for them. At the end of the road, sacrifices need to be made.
