The film follows the story of the fictional martial artist Guo Jing (Zhan Xiao) during the tumultuous Southern Song dynasty. Amid the ongoing conflict between the Mongols and the Jin Dynasty, Guo Jing embarks on a quest to find Huang Rong (Dafei Zhuang), a woman he encountered during his two-year journey across the Central Plains, where he honed his martial arts skills under the guidance of the legendary Seven Freaks of Jiangnan. It was Huang Rong who directed him towards a more exceptional mentor, Hong Qi Gong (Jun Hu), from whom he mastered the formidable martial art known as the Eighteen Dragon-Subduing Palms.
As fate would have it, a catastrophic incident leaves Huang Rong severely injured, prompting Guo Jing to carry her on his back in search of Reverend Yi Deng (Hsing-Kuo Wu). At this crucial moment, he learns sacred healing techniques from the elusive Nine Yin Manual, which later becomes a significant element in their lives. Together, they travel to her island, but tragedy strikes when Guo Jing discovers that his former masters have been brutally murdered—an event that leads him to mistakenly suspect Huang Rong's father is responsible, leading him to part ways with her.
In a gripping twist, Huang Rong falls into the clutches of the Jin-loyal martial arts master Ouyang Feng (Tony Ka Fai Leung) and his henchmen, who are on a relentless pursuit for the Nine Yin Manual that she and Guo Jing possess. Using her wit, Huang Rong creates discord amongst Ouyang Feng's followers, allowing her to escape her bonds and leap into the river, evading capture.
Meanwhile, Guo Jing reflects on his decision to abandon Huang Rong and cleverly leaves behind small pinwheels as a trail of breadcrumbs for her to follow. While resting near a river, he overhears a conversation amongst a group of Mongols and encounters Tolui (Alan Aruna), one of the Mongols suffering due to a poisoned river. In a heroic display of his learned martial arts, Guo Jing intervenes, defeats the villains, and uses his healing techniques to save the poisoned victims.
Huang Rong’s escape is fraught with danger as she navigates a chaotic town filled with skirmishes. Amidst the turmoil, she stumbles upon one of Guo Jing’s pinwheels, leading her to follow his trail back to the Mongol camp. Once reunited with her mother, Li Ping (Ada Choi), the joyous reunion is overshadowed when they learn that she is betrothed to Guo Jing by her father, a revelation that brings heartbreak to Huang Rong.
As tensions rise, Guo Jing finds himself caught between his mother’s wish for him to protect their homeland from invasion and his feelings for Huang Rong. When he confides in his mother, chaos ensues as Hua Zheng bursts in, leading Guo Jing to declare he has no intention of marrying her. This declaration sends Hua Zheng into a rage, vowing vengeance on the woman who has captured Guo Jing's heart—unbeknownst to her that it is indeed Huang Rong.
The plot thickens when a martial arts demonstration by Guo Jing is interrupted by the arrival of Ouyang Feng and his followers. In a dramatic turn of events, Huang Rong saves Hua Zheng from Ouyang Feng's blade by offering him a fake copy of the Nine Yin Manual, thereby securing a temporary reprieve but affording her no true solace. Determined to not let love get in the way of duty, Huang Rong departs from the camp, believing it best for Guo Jing.
Amidst escalating conflicts, Genghis Khan (Bayaertu) decides to lead a march against the Jin capital. However, Guo Jing, committed to his homeland, rejects the call to arms. This act of defiance leads to grave consequences as he faces execution for his insubordination. Just as despair seems inevitable, Tolui advocates for him, though Guo Jing's family finds their path to freedom blocked. Tragedy strikes when Guo Jing’s mother sacrifices her life, believing that his destiny lies in battling for his homeland.
With the aid of Hua Zheng, Guo Jing escapes and joins forces with Huang Rong once more as they pledge to aid the Song Dynasty against impending threats. Just before the Mongols clash with the Song forces, Ouyang Feng, deranged by the real and fake manuals, unleashes chaos on the battlefield. Guo Jing intervenes, leading to a fierce confrontation between him and Ouyang Feng. Ultimately, Guo Jing emerges victorious, saving Genghis Khan and solidifying his resolve to defend his homeland.
In a poignant moment, Guo Jing stands before the Mongol army, famously proclaiming that conquest must come at his own expense, advocating for peace and urging Genghis Khan to reconsider his actions. Through heartfelt dialogue about the ideals of heroism and safeguarding one’s people, Guo Jing ultimately persuades him to retreat, thereby preserving the Song city from an impending disaster. This film is not just a tale of martial arts but also a profound exploration of love, duty, and the courage to protect one's land.
