While questioning his faith in God, the Catholic priest, Father Ezekiel O'Sullivan, leads the annual archaeology tour for the local community college. Heading to the spiritual Mayan ruins of Todo Santos in Mexico, against the backdrop of the Grand Festival of the Laughing Dead, O'Sullivan and a motley crew of tourists are in for a shock when they cross paths with Dr Um-tzec, a wicked occultist bent on ushering in a new era of darkness. As warm, bright-red sacrificial blood flows, the unsuspecting visitors meet their horrible ends, paving the way for the advent of an unspeakable, ancient terror from the depths of history. Is O'Sullivan prepared for the ultimate confrontation with the blackest of evil?