Shanghai Noon 3 imagines a new adventure that brings Chon Wang and Roy O’Bannon back together for the most unpredictable journey of their lives. After years of going their separate ways, the two unlikely heroes reunite when a mysterious letter arrives from China, warning Chon that an ancient imperial artifact has been stolen—and that its disappearance could destabilize the entire region. Though Roy initially refuses, tempted instead by a new life as a showman in New York, the threat of global chaos—and a generous promise of payment—pull him back into the saddle once more.

Their mission begins in bustling Shanghai, where Chon is shocked to find his once-quiet hometown overflowing with foreign influence, political tension, and dangerous opportunists. Roy, meanwhile, is far more captivated by the city’s nightlife than its dangers, which immediately places them in the crosshairs of a powerful criminal alliance. When the pair discover that the artifact is tied to a secret society aiming to overthrow the new imperial government, their task becomes far more complicated than a simple recovery mission.

Chon insists on a disciplined, straightforward investigation, but Roy’s impulsiveness continually derails their plans. His attempts to charm informants, bribe officials, and bluff their way into restricted areas lead to comedic disaster after disaster. Yet, despite the chaos Roy creates, his unorthodox methods also uncover clues no one else could have found. Together, their mismatched styles expose a conspiracy stretching from Shanghai’s opium dens to high-ranking officials within the court.

As they chase the thieves across the countryside, Chon and Roy encounter new allies, including a fiercely independent martial artist determined to protect her village from the society’s violence. Her sharp wit and unmatched skill impress Chon and intimidate Roy, who tries desperately—and unsuccessfully—to win her admiration. With her help, the two heroes learn the true power of the artifact: it contains encoded messages revealing the society’s entire network.

The final confrontation takes place on a moving steam train barreling toward Beijing, where the conspirators plan to launch their rebellion. Chon faces off against the society’s deadly enforcer in a breathtaking martial arts duel atop the train cars, while Roy scrambles through the passenger cabins causing chaos, accidentally saving the day more than once.

In the end, the artifact is restored, the conspiracy is exposed, and Chon and Roy reaffirm their unshakable—if exasperating—friendship. Though the world is once again safe, Roy is already dreaming up their next great adventure, much to Chon’s dismay.