Undercover Hong Kong cop Kit is sent to a hellish Thai prison after his cover is blown. As his supervising uncle Wah tries to discover his whereabouts, Kit learns the jail is the centre of an organ trafficking ring run by degenerate cut throats. One of the few honest guards is Chai (ONG BAK superstar Tony Jaa in his finest role) whose dying daughter desperately needs a bone marrow transplant. And so the scene is set for an audacious turbo-charged thriller showcasing Hong Kong action film making at its stunning best.