In 16th‑century China, courage meets cruelty as Ming guard Fong Sau-ching Yuen Biao relentlessly pursues the brutal Feng San Yuen Wah, a villain infamous for raping and killing women. When Feng San murders the princess, the enraged emperor Anthony Wong Yiu-Ming gives Fong one last chance to bring the killer to justice within 20 days. The chase takes a shocking turn when Feng San steals the priceless Black Jade Buddha, a magical artifact that grants time travel, and the two men are whisked three centuries into the future.
On a windswept cliff, a titanic clash of martial arts erupts between the two rivals, a battle that ends only when both men tumble into a glacier and are frozen in time. They are later thawed out by scientists, and Fong—no longer merely a guard—must navigate life in 1980s Kowloon. The modern world—with its electricity, televisions, and strange comforts like toilets—presents a daunting new terrain. Enter Polly Maggie Cheung, a femme fatale who knows of Fong’s martial prowess and offers him a way to survive: she hires him as her servant and bodyguard in exchange for helping him obtain an ID card. Yet Fong feels a twinge of shame at becoming a servant to a woman, a stark reversal of his royal‑guard duties.
Meanwhile, Feng San continues to operate as a thief for a local crime boss, escalating his brutality. He murders his boss after a failed attempt to rape the boss’s girlfriend, and the fate of the girlfriend is left even more brutal in his wake. As Fong learns of Polly’s past and the cruel truth of Feng San’s escapes, he vows to resist becoming merely a tool for hire. A newspaper report about a woman murdered in the same grisly way Feng San favors jolts him—he realizes the killer remains at large.
The villain’s thirst for power intensifies when he discovers the Black Jade’s wheel has been moved to a Hong Kong exhibit. He loots firearms from an arms dealer, planning to return to the past armed with modern weaponry to seize the dynasty. Fong, intent on completing his duty, trains relentlessly and crafts a sword suited to the coming confrontation. He reluctantly leaves Polly behind, not wishing to drag her into the perilous mission.
At the exhibit, Feng San finds a note on the wheel written by Fong, summoning him to the roof for the Black Jade. On the roof, the two survivors face off one final time: Fong asserts that he will arrest Feng San and return him to justice for his crimes, fulfilling his duty to the emperor. The battle is brutal, and Fong emerges victorious, impaling Feng San on shards of broken glass. He activates the Buddha’s wheel, sealing the time‑travel device’s next arc. Polly arrives too late to stop him, her heart heavy as she witnesses the climactic moment.
In the aftermath, Polly quits the underworld and starts a new life running a corner store. As she takes out the trash, she encounters a man who resembles Fong, hinting at a possible reincarnation. She shouts with joy that Fong may still be alive and, despite the man’s confusion, she leaps toward him, clinging to a hope that love—and justice—endure beyond time.
