Late-stage flashbacks reveal the film's major twist: Tae-ok is not Tae-yul's biological daughter, but the secret infant princess of the deposed King Gwanghaegun. Entrusted to Tae-yul during the night of the coup, he chose to raise her in complete anonymity in the mountains to protect her from political execution.
As the narrative culminates, Min Seung-ho seeks atonement for Joseon's humiliation and duels Gurutai to uphold martial honor, sacrificing his life in the process. Tae-yul then mounts a solitary assault on the Qing fortress, cutting through riflemen and infantry. During the climactic duel with Gurutai, Tae-yul's eyesight fails completely into total darkness. Relying purely on blade vibrations, footsteps, and breath sounds, Tae-yul parries Gurutai's dual swords and strikes him down.
In the resolution, despite learning of her royal heritage, Tae-ok rejects dynastic claims to stay with Tae-yul. The film ends with Tae-ok taking her blind father by the hand and leading him peacefully back into the misty sanctuary of the mountains, affirming that their paternal bond transcends royal blood.