The ghostly apparition of a young woman is witnessed by an 18th Century French Lieutenant in Napoleon's army. After two failed attempts to keep up with her, Lt. Andre Duvalier (Nicholson) heads to the castle of Baron Von Leppe (Karloff), where he notices a painting of the Baron's late wife Ilsa, who looks identical to the ghostly woman. Duvalier is now determined to unravel the castle's mystery, and the Baron's hidden secrets. Though officially credited to Roger Corman, The Terror had a total of five collaborative directors, including Nicholson himself, and Francis Ford Coppola.