Three warriors of the Chinese Imperial Guard (played by actors Rongguang Yu, Ya Hi Cui and Eric Chen) have accompanied Jackie Chan's character (Chon Wang) from China to the Old West in the United States in order to assist him in his mission to rescue the kidnapped Chinese princess Pei Pei (played by Lucy Liu). Famous and amiable outlaw Roy O'Bannon (played by Owen Wilson) attempts to rob the train as it crosses Nevada. Mishaps ensue, and Jackie's character is separated from the Imperial Guardsmen.
The film primarily follows the story of Jackie Chan and Owen Wilson's travels. The next time we see the Chinese Imperial Guardsmen, we see that they have been travelling with a family of Latter-day Saint pioneers.
While the family takes a break from travelling to rest and eat, the guardsmen perform some exercises with their swords. In a brief scene that begins 31 minutes and 24 seconds after the start of the film, we see the pioneer family, and they discuss who they think the guardsmen are.
Below is the dialogue from this scene, as it can be heard in the movie:
Jedediah's wife (Valerie Planche): They don't look like any injuns I ever seen, Jedediah.
Jedediah (Rick Ash): That's because they're no injuns, woman! They're Jews!