Bucktooth So has opened a Po Chi Lam branch in America. Wong Fei Hung, Clubfoot, and 13th Aunt, who is now Wong's fiancée, travel across the Pacific Ocean to visit him. While travelling by carriage through the wilderness they pick up a friendly cowboy named Billy who has nearly died of thirst. As the party Wong is travelling with stops to have lunch, a band of hostile Native Americans ambush the party. Wong, Clubfoot, and 13th Aunt escape unharmed but their carriage slides off a cliff and into a river. 13th Aunt and Clubfoot are rescued and taken to Bucktooth So's clinic. Wong, however, dashes his head into a rock and loses his memory. He is picked up by a Native American tribe.

Back in the town Bucktooth So is staying in the Mayor is causing trouble for the Chinese by making oppressive rules which Billie tries to stop. Meanwhile, Wong's adopted tribe is in trouble with a more powerful Indian tribe. Their leader is a fearsome warrior who injures one of the braves on Wong's side, Fierce Eagle, the chieftain's son. However, Wong surprisingly defeats the rival chieftain and half his men through his amazing martial arts ability. The rival tribe flees in shock. Wong is eventually brought to town by the Indians. There his friends discover that his memory loss and Clubfoot and try all means to help him recall the past.

Wong finally regains his memory, but forgets everything that has happened in the period when he had amnesia. The Mayor is in debt and decides to hire a Mexican bandit (Joe Sayah) to help him rob the bank so he can abscond the town with a ton of cash. The robbery is successful and Po Chi Lam is framed for it. Wong and the others are scheduled to be hanged; however, the Mexican bandit discovers he has been left US$400,000 short by the governor and goes back to the town. In the fight that ensues the governor is killed and Wong captures the bandit to prove their innocence. At the end, Wong, 13th Aunt, and Clubfoot wish Bucktooth So good luck and head back home to China.