When Francis Barnard (John Kerr) goes to Spain after hearing of his sister's death her husband, Nicholas (Vincent Price) tells him that she died of a blood disease, but Francis finds this highly unlikely.
Nicholas was the son of the most brutal and unfeeling of torturers whom worked with the Spanish Inquisition. Now Francis thinks that it was ecxtreme fear that brought the downfall of his sister and that she may even of been buried alive.
Now strange things are starting to happen in the Medina castle.