The long arm of the Inquisition, or the "Holy Office," reached at least as far as 16th-century Mexico (known as New Spain at the time). Many Spanish Catholics of Moorish or Jewish origin found it expedient to flee to the New World to escape the suffocating attentions of the Inquisition. In Spain, simply being descended from these suspect peoples is sufficient to guarantee a gruesome death by immolation. In the New World, it took slightly more. This 1974 Mexican film deals with the suffering of one family of conversos who are secretly practicing Judaism and are betrayed to the Inquisition by a family member. Interestingly, a small family clan of such secret Jews was discovered in New Mexico as recently as the late 1980s. They managed to keep their faith a secret for nearly five hundred years.
~ Clarke Fountain, All Movie Guide