Jaguar Paw's village is the victim of one such attack and he is carted off to be sacrificed, but not before he manages to safely hide his pregnant wife and child in a hole in the ground. What follows is two hours of watching Jaguar Paw go from one bad situation to another as he attempts to get home and save his family.
Each of these bad situations typically involves a lot of Mayans bashing each other's heads in with clubs in what I can only describe as one of the grizzliest and most unnecessarily bloodthirsty films I have ever seen. It's not that I'm squeamish about a bit of blood (or skull or brain or entrails) but that all the gore in this film seems to have only been included for the sake of it.
Unfortunately, Mel Gibson is up to his old trick of trying to ramp up the emotional tension by including more blood, the same trick he tried (unsuccessfully) in The Passion of the Christ.
Another major flaw in the film is that there really is no storyline – like War of the Worlds (a much better film), this is just an exercise in keeping the suspense going as Jaguar Paw gets beaten up, abducted, beaten up, tries to escape, gets beaten up and so on until the inevitable conclusion. The main character hardly says a word and is very difficult to relate to or care about as a result. In fact, one of his friends, a big, strong guy who is introduced in the opening scene, is a much more likeable and interesting character.
There is a mystical theme to the film, hinting at a bit of spiritualism, but this witch-doctor theme is not really explored very thoroughly. There probably wasn't enough time to include that plot thread after all the braining and bleeding. There are also gaping holes in what little plot there is, because Jaguar Paw seems to have the healing ability of Wolverine.
Overall though, if you ignore all these problems, it's a vaguely entertaining action film that doesn't try to preach its message too loudly and instead focuses on the simple story it is trying to tell. I wouldn't watch it again, but it is tolerable enough to watch once if you really feel the need.