Advertising company staff Mo Tak-fai [Andy Lau] and his friend Lai Chi [Natalis Chan Pak-Cheung] go to mainland China for a business trip. Chi smuggles some relics, triggering a police chase that forces the pair to flee into a cave to escape capture. In the dim shelter, Chi is bitten by a poisonous snake, and the duo discovers a medicine tied to an ancient hero named Long Jianfei. Chi shares this discovery with Tak-fai, and the miraculous medicine not only detoxifies Chi but also endows both men with heightened internal strengths. In the same fateful moment, they rescue Princess Yunluo, Joey Wong Cho-Yin and her maid Xiao Man, Cutie Mui Siu-Wai, who had slept for 800 years in the Yuan Dynasty. Their rescue, however, stirs an old menace: Tian Can, Yuen Wah, a two-hundred-year-old evil martial arts expert who has waited for such an opportunity to return.
Back in Hong Kong, Tak-fai and Chi remain skeptical about the extraordinary events, but they do not abandon their newfound companions. They bring Yunluo and Xiao Man to the bustling city, where Yunluo quickly learns to navigate modern life with surprising ease. The two men, meanwhile, try to make sense of the powers surrounding them and the responsibilities that come with the ancient relics now in their possession. To balance danger with hope, Yunluo decides to help Tak-fai grow his abilities, while Chi trains with the new and unusual aims he possesses.
As the layers of their training unfold, Yunluo helps Tak-fai master the Buddha's Palm, a legendary discipline that could tip the scales in their favor. Chi, on the other hand, shows promise in the Seven Rotary Slice technique, though his raw talent marks him as the slower learner of the pair. The tension rises when Tian Can appears again, swiftly overpowering Tak-fai in a brutal display because Tak-fai has not yet mastered the Ten Thousand Buddhas technique. The confrontation forces a harsh test: Tian Can drags Tak-fai into a dangerous trap and compels him to eat a cursed silkworm. The bite of the silkworm inflicts excruciating pain whenever Tian Can drums, turning Tak-fai’s resolve into a grueling ordeal.
The following day, Tian Can embarks on a rampage. He robs a bank ATM, menaces Tak-fai and Chi by threatening to drag their boss into danger, and defeats the police who converge on the scene. Yunluo steps forward to shield the two men, but Tak-fai sustains additional injuries in the chaos. Just when hope seems fragile, they cross paths with Yim Chan, leader of a supernatural performing troupe from China, who offers healing and channels energy to Tak-fai, accelerating his recovery and sharpening his focus. Bolstered by this aid and renewed determination, Tak-fai finally achieves the mastery of the Ten Thousand Buddhas.
With his new power, Tak-fai stands ready to confront Tian Can in a climactic showdown. The final duel tests their limits, as Tak-fai unleashes the full force of the Ten Thousand Buddhas to cripple Tian Can’s martial arts abilities. In this long-awaited clash, Tak-fai emerges as a true hero, having protected his companions and chosen to use his hard-won strength to defend others, signaling a new era of courage and responsibility for the group.
