In Mexico, an archaeologist releases the evil spirit of a devil child from a tomb of an ancient tribe called Sanzia that worshiped Satan on Earth and dies in an accident.
Immediately after, an American family with two children arrives to live and reactivate a factory of dolls in a site nearby the archaeological field. Elliot Read invested the savings of his family in this business to manufacture dolls.
He finds many dolls left by the previous owners of the factory, and gives one of them, which is possessed by the fiend, to his daughter Jessica Read. The girl changes her behavior, speaks an ancient language and the maid tells to the mother Marilyn Read.
Meanwhile, the archaeologist Karl Resnick arrives to investigate the finding of his colleague. However, the demon has been already released, threatening the locals and the Read family.