Intrigues and secrets come together because of a woman, who has the protection of the parish priest.

Produced on a grand scale, the Mexican Talpa relates the simple story of two brothers. The older of the siblings, Tanilo (Victor Manuel Mendoza) is a well-to-do family man; the other, Estaban (Jamie Fernandez), is one step above a wastrel. When Tanilo is felled by illness, Estaban is forced to take over the family's blacksmith business. He also inaugurates a romance with Tanilo's attractive young wife Juana (Lilia Prado). Punishment is eventually doled out in a manner which suggests that God Himself is exacting retribution on the adulterous couple. Originally released at 87 minutes, Talpa was pared down to 73 minutes for American consumption.

During the mid-1970s, in the Mexican state of Guanajuato, authorities discover a clandestine burial ground. The corpses are from murdered prostitutes. The suspects are three sisters known as "Las Poquianchis".

In 1965 Mexico City, Flavia, a wealthy yet lonely schoolgirl, befriends Veronica, a young orphan girl who has a fascination with witchcraft. Veronica convinces Flavia that she is a real witch and forces her to be her assistant. The children's games gradually become more serious and Veronica demands more from Flavia.