When Lo Fong (Roger Yuan) kidnaps the Emperor's daughter, Princess Pei Pei (Lucy Liu), and takes her to America, the Emperor sends his best Imperial Guardsman to find her. Chon Wang (Jackie Chan), one of the Emperor's least distinguished guards, insists on joining them. He feels responsible for the kidnapping and wants to make amends. However, while the rescue party scours the West, Chon Wang gets separated from the group and soon becomes lost. When he crosses paths with Roy O'Bannon (Owen Wilson), a small-time outlaw, the two become unlikely allies.