"The emperor must be slowly destroyed from within." The assassin So-hwa enters the palace as a court lady to seduce the tyrant Emperor Yugeon. However, Yugeon suffers from mysophobia and a severe mental disorder, refusing to let any woman near him. “If you touch me, you'll be tainted too.” On a night when the emperor’s madness flares, during his bedtime guard shift, So-hwa tries to bring him down from within his bedchamber. But as Yugeon begins to fall for So-hwa, he gradually becomes obsessed with her.