Cristian and his sister, July, travel from Madrid to El Garraf with their parents and their little brother to spend the Holy Week in their old vacation home. They learn the legend of Melinda, a girl wearing a red dress that got lost in the labyrinth near the house, who helps people that also get lost in the spot. Carlos, a visiting family friend, tells the siblings that there are different, more sinister versions of the legend. July and Cristian use two hand-held cameras to explore the labyrinth and investigate the mystery of Melinda, until something horrible happens.