The story is inspired by Basque folklore and follows the character of Usue (played by Uma Bracaglia), a young orphan who stumbles upon a mysterious and cursed blacksmith named Patxi (played by Kandido Uranga). Patxi lives in isolation and is rumored to have made a pact with the devil, a claim that seems to be true when the devil (played by Javier Botet) arrives to reclaim the soul he was promised.

As Usue investigates the blacksmith’s dark past and the sinister pact he made, she uncovers the truth about Patxi’s curse and the supernatural forces at play. The film delves into themes of redemption, guilt, and the battle between good and evil, all set against a backdrop of eerie and atmospheric horror.