In 1658, a beautiful woman named Eugenia discovers that her lover, by whom she had three children, is going to marry someone else in The Vengeance of the Crying Woman. Brokenhearted and scorned, she decides to make a deal with the devil to get revenge. In doing so, Eugenia poisons herself and her children, vowing to return as La Llorona and take every firstborn child of her lover's descendants. The time has come and La Llorona has returned to the present to exact her revenge. Santo, with the help of his friend Mantequilla Napoles, figures out that the only way to end La Llorona's curse is to retrieve the medallion from her tomb, which holds the key to a treasure she left behind, and give it to a children's charity.