In 1960s Spain, 9-year-old Javi and his friend Carlos are both fascinated and scared by an empty house in their village. Javi's older brother insists a crime was once committed there, and eerie voices are sometimes heard.
The mystery captivates Javi, especially as it seems linked to his father's death, who used to meet a mysterious woman there. Returning to their secluded mountain home, Javi finds another locked room, shrouded in secrecy. As he investigates, he uncovers adult secrets and lies.
According to the film's producer, Secretos del corazón is "a poetical and emotional movie that can share with Hollywood's big overproductions' special effects."