The film is set in an era of intense political power struggles. Jeong Panseo, driven by an old grudge, vows revenge on the Kim Panseo clan. Kim Panseo, asserting his innocence, refuses to flee and is eventually captured and killed by Jeong Panseo. Kim Panseo's wife and their only daughter, Guseulagi, flee to the mountains with the help of the loyal Park Owijang. However, Jeong Panseo's pursuit extends to the mountains, and Guseulagi's sick mother dies in an attack by Jeong Panseo's henchmen. Guseulagi, filled with a thirst for revenge, disguises herself as a man and infiltrates Jeong Panseo's house as a servant. Under the pseudonym Tteoksoe, she attends to Jeong Duryeong, Jeong Panseo's only son. Jeong Duryeong, who despises his greedy father, befriends Tteoksoe while teaching her to read. Although Guseulagi is tormented by guilt for deceiving Jeong Duryeong, who is kind to her, she cannot give up her revenge. She poisons Jeong Panseo's food, but Jeong Panseo, suspicious, tests it with silver chopsticks. Jeong Duryeong defends Tteoksoe, who becomes a suspect. Guseulagi gradually falls in love with Jeong Duryeong. Unable to bear loving her enemy's son, she secretly flees Jeong Panseo's house but is caught by Jeong Duryeong, who discovers her true identity. Jeong Duryeong harbors resentment towards Tteoksoe for deceiving him but soon realizes he has fallen in love with her himself. They flee to escape Jeong Panseo's pursuit, but Guseulagi is captured. On the day of Guseulagi's execution, Park Owijang rescues her, and they escape together with Jeong Duryeong. Jeong Panseo pursues Guseulagi and Jeong Duryeong, while Park Owijang pursues Jeong Panseo. Finally, Jeong Panseo dies in Park Owijang's attack when his carriage tumbles down a cliff.