Rescuers try to reach plane crash victims that are trapped on an isolated Mexican island populated by mutant baboons. Ron Perlman stars as a troubled guide hired to lead the mission.

A private plane carrying the daughter of a rich businessman crash-lands on the uninhabited island of San Miguel off the coast of Mexico, an island regarded by the locals as cursed. The businessman's Chief of Security, Scott Davis mounts a high-tech mission to rescue the survivors, and in his search to find a guide, comes across Frank Brodie, a man who was on the island ten years previously. Davis finds Brodie to be a brooding, reclusive drunk, haunted by his experiences on the island, and Brodie tells Davis that it isn't worth mounting a rescue mission as the survivors will, by now, be dead. Brodie, however, decides to tag along, bringing along a veritable arsenal of weapons and a fatalistic attitude, ridiculing Davis' plans as naive. Accompanying them is Tara Matthews, a young woman purporting to be a medic, and Davis' second-in-command, Eddie Mendoza, a down-to-earth practical man who very quickly realizes Brodie knows what he is doing and is inclined to believe what the man says. Bringing up the rear is Kovacs, the tech-whiz of the group, complete with thermal-re-con equipment and a high-tech communications system. On landing on the island it soon becomes very clear that they are not alone - something is out there watching them, and the trip rapidly descends into a nightmare. Brodie then informs them of the reason he left the island ten years previously - he was the only man left alive after a disastrous experiment in mutant animal genetics leaves the place infested with creatures that have only one aim in life - and that is to kill...—Helen Chavez