Chon Wang (Chan) and Roy (Wilson) team up again when Wang's father is killed while guarding the Imperial Seal. Wang's sister Li (Fann) has witnessed the crime and followed the culprit to London, where the duo also converge. There they find a plot by frustrated royal heirs Rathbone (Gillen) and Wu Chan (Yen) to overthrow the British and Chinese thrones. Chan and Wilson still have their great chemistry, and the script gives them plenty of opportunities to show it. Chan choreographs the fight scenes like numbers in a musical to excellent effect, paying homage to "Singin' in the Rain" as well as some of his influences such as the Keystone Kops, Harold Lloyd, Abbott and Costello, and Charlie Chaplin. Victorian-era cultural references are fun to catalogue as well.