N this giddily frenetic follow-up (though not a sequel) to modern martial arts epic KILL ZONE (aka SPL: SHA PO LANG), action icons Tony Jaa, Wu Jing and Zhang Jin team up with Hong Kong megastars Simon Yam, and Louis Koo for a breakneck story of dirty cops, prison riots, and black market organ transplants, all brought together by a non-stop series of inventive, bone-crunching setpieces.