This is one of the first well made documentaries I have seen that really explains the science behind the martial arts. CGI work is done by the same animators responsible for the natives, and we are shown what happens to the muscles and bones of the fighters during combat. Very well made fight scenes demonstrate most medieval weapons made, and are at least as entertaining as any Crouching Tiger Hidden Dragon fight. Interspersed throughout the whole thing, is the story of Mullins, a five time martial arts world champion who is coming out of retirement to compete once again. A very fascinating look at the secret world of martial arts. I would definitely recommend this to anyone with any interest in the field.