A 40-year-old taxi driver is found dead at Yakcheon. Hyun-woo (KANG Ha-neul) is a witness, but charged with a murder despite his cry for innocence and serves 10 years in prison. After being released from prison, Hyun-woo tries to lead a quiet life with his mother, but the stigma of being a 'murderer' is hard to rid of. Meanwhile, lawyer Joon-young (JUNG Woo) just lost a huge class action suit. Heavily in debt, he decides to find a job at a law firm. While offering pro bono services arranged by the firm, Jun-young meets Hyun-woo, and they begin their journey to prove Hyun-woo's innocence.