Two twins are separated at birth, one becoming a streetwise mechanic and the other an acclaimed classical concert conductor. Finally meeting in adulthood they each become mistaken for the other and entangled in each other's world.
Even for Chan's earlier work, you don't need subtitles to understand the significance of a killer roundhouse. Oh, and apparently he's coming out with a new flick next year at 62 years of age. Proof: karate > human mortality.