Summer 1978: an English couple are going through a difficult patch in their relationship, and so decide to spend the summer in the house that their friends have bought in the north of Spain.

Very much off the beaten track, the house seems ideal for some peaceful holidays. But their tranquillity is abruptly shattered when they discover a girl with horribly deformed hands locked away in a cabin in the woods. Filthy and unable to talk, the girl is obviously terrified and so the couple decide to take her to the police. But their attempts to help the girl are hampered by the denseness of the forest, as well as by a group of local villagers who seem determined to keep the girl in these conditions....