Trevor Blackburn is accused of murdering his girlfriend, Faith, in a brutal ritual. He's sentenced to live in an experimental rehabilitation community and falls into a coma. When he wakes up, he meets the mysterious Dr. Ek, who tortures Trevor in an attempt to learn the whereabouts of a powerful occult book. As other patients start to disappear, Trevor begins to wonder who and where he really is.
A busload of travelers and their disgraced priest tour guide, on the hunt for Aztec ruins, decide to stop in a Mexican village on the eve of the Day of the Dead. Unbeknownst to them, a local doctor plans to begin a diabolical ritual intended to bring about Hell on Earth.