Though it places his own life in danger, a look-alike commoner secretly takes the place of a poisoned king to save his country from falling into chaos.

October 26, 1979, a presidential assassination shakes the nation. Taking on the defense of Park Tae-joo, the secretary involved in the presidential assassination, lawyer Jung In-hoo enters what would be South Korea's most notorious political trial. Despite Park Tae-joo facing a predetermined sentence due to his military status, Jung In-hoo fights tirelessly to ensure a fair trial, enraged by the trial's unfair proceedings.