Certainly someone, somewhere, must be offended by the premise of Chocolate. An autistic girl learns karate by watching kung-fu movies on television and then, after learning that her mother doesn't have the money for chemotherapy, she goes on a rampage to collect from debtors. Surely this autism-fu is insensitive—the American trailer says, "From the people who brought you Ong-Bak, comes a special-needs girl with a special need to kick some ass"—but it's also the premise for one of the best kung-fu movies to be released in America in recent memory.

As Zen, JeeJa Yanin is the ideal kung-fu heroine: She looks small and vulnerable until she starts to actually attack. Her limbs strike out like daggers in a perfect sphere around her body, and in some sequences it appears that she could kick the back of her own head if she stretched a bit more beforehand. She also seems perfectly unselfconscious when portraying the spazzy, inward motions of an autistic girl. She doesn't talk so much as bleat with frustration and anger, but it's not some elementary-school mockery of a mentally challenged child. There's real acting there.

Not everything about Chocolate is as note-perfect as Zen's portrayal. The first five minutes—the scenes that are meant to establish the story—are a confusing hash that only make sense on repeat viewings. And none of the other characters are developed at all. But the action scenes are exquisite. Zen goes from place to place in a small Thai city—a slaughterhouse, a warehouse, a seafood packing plant—exacting vengeance on people who owe her mother money, and things escalate as they should until the final 20-minute-long action sequence which involves an elevated train, a three-story building, and a full city block. The bad guys crash with their entire bodies into window ledges and hanging signs before slamming into the pavement below, and the choreography is reminiscent of Jackie Chan's early inventiveness without the unnecessary attendant precociousness. Her preternatural skill at violent—and stuntman-less—kung fu makes every American Jet Li movie look like a Merchant Ivory film. It's been a long time since an action sequence sent literal chills up and down my spine, but Chocolate delivers that sensation repeatedly.