A terror is stalking the land: people are disappearing daily, their bodies appearing covered in savage gashes coupled with precise surgical cuts. The legend of the 'Werewolf of Allariz' spreads across the land like wildfire. When Barbara (Elsa Pataky) falls in love with travelling vendor Manuel Romasanta, she is at first besotted with him - but soon begins to be suspicious of him. What has happened to her sister, who - after being escorted by Romasanta to the city - seems to have disappeared forever.