Being a sequel-in-name-only, Soi Cheang's Kill Zone 2 requires no foreknowledge of Kill Zone — and people in the know will tell you that film's true name wasSPL and that this film's real title is< i>SPL 2: A Time for Consequences. This convoluted naming history is appropriate for a film that — not uncommonly for Hong Kong action films — is somewhat overstuffed with characters and plot. The primary and most interesting thread involves Kit (Wu Jing), an undercover cop who gets thrown into a Thai prison, where honest guard Chatchai (Tony Jaa) needs to find a bone-marrow transplant for his emoji-expert daughter Sa (Unda Kunteera Thordchanng) — and for whom Kit is the only known matching donor. It's all mostly an excuse for the gonzo action sequences, and unlike certain recent Hong Kong movies that got bogged down in moralizing — yeah, you, Wild City —Kill Zone 2 delivers the goods in this post-Raid environment. The climactic boss fight with the warden (Zhang Jin), in which the misses are as important as the hits, is worth the price of admission, while the debt of the film's gunplay to the seminal work of John Woo is acknowledged by a shot of a billboard for Woo's 1986 A Better Tomorrow. It's always important to honor your elders.