Hyeong Ju lives an ordinary life. One day, he loses his closest colleague—his sole motivator in life.

Hyeong Ju finds himself in a time ages before Sun Ho's murder. Ga Hyeon also gets her share of throwbacks.

What seemed to be an opportunity for a better life brings Ga Hyeon to a downward whirlpool in life.

After Ga Hyeon loses Ju Young in an accident, she decides to find the driver who murdered her friend.

The police find the dead body of Yeon Soo at the part where she met Ga Hyeon. Her testimony brings in doubt.

After the investigation occurs at the police station, Ga Hyeon helps Hyeong Ju out in finding Jung Tae.