La misteriosa enfermedad de su hermana pequeña hará que Nala y su familia viajen a la casa de su abuela para encontrar la cura. En este lugar, ella aprenderá sobre leyendas locales de brujas que se alimentan de la sangre de los niños para permanecer por siempre jóvenes. Mientras más conoce Nala sobre estos seres diabólicos, más se convencerá de que su abuela podría ser una bruja.

Luna is sick and no treatment seems to work. Her desperate parents take her to the Mexican countryside to seek an alternative treatment, where they leave Luna and her older sister Nala in the care of Josefa, their grandmother. Acting in what initially seems to be an eccentric way, Josefa becomes far eerier once the parents have left. After listening to a bedtime story from Josefa’s housemaid, Abigail, Nala is convinced the stories are true, and something is after her little sister Luna. As dreadful events befall Luna, Nala gathers her courage, hellbent on defending her sibling against the evil lurking in the house.