I. Synopsis
This is a story of three swordsmen, Poong-cheon (Bae Soo-bin), Seol-rang (Jeon Do-yeon), and Deok-gi (Lee Byung-hun), who led an uprising during the Goryeo era. When their desire for freedom and justice is about to be fulfilled, Deok-gi betrays them, leading to the death of Poong-cheon, and to Seol-rang disappearing along with Poong-cheon's infant daughter Hong-ee. When Seol-rang leaves, Deok-gi intones the prophecy that "You, no, not just you, but you and I both will be killed by Hong-ee."
Eighteen years later, Seol-rang, now called Wallso, is a blind woman with two children who manages a tea house at Byukran port. Determined to take revenge on Deok-gi, Wallso tries to teach Hong-ee (Kim Go-eun) to become a master of the sword, but Hong-ee (who changed her name to Seol-hee) is much more interested in day-to-day affairs than what happened to her father in the past.
One day, a big sword match hosted by the powerful military ruler Deok-gi (now known as Yoo-baek) is held in the market. Seol-hee participates in the match despite Wallso's objections. As the match progresses, she ends up fighting Yull, who is the master of the sword.
Yoo-baek realizes that Seol-hee's skill with the sword is similar to Seol-rang's, whom he had once loved. Yoo-baek orders his subordinates to catch Seol-hee, but she is able to run away. That same night, Seol-hee learns how her father, Poong-cheon died. Wallso tells her that there are two enemies that Seol-hee is destined to vanquish: Yoo-baek, and Wallso herself. Shocked and desperate, Seol-hee leaves home: the beginning of a long journey of revenge.
