AllMovie

After his true identity is exposed, undercover cop Kit (Wu Jing) is sent to a corrupt Thai prison by the gang he infiltrated, while his police unit erases all evidence that he was ever an officer. There, a guard named Chai (Tony Jaa) discovers that Kit is a bone-marrow match for his daughter, who desperately needs a transplant. The unlikely partners must find a way to secretly escape from the brutal prison and save Chai's daughter. Pou-Soi Cheang directed this martial-arts action thriller.