Thanks to Black Sunday and The Long Hair of Death, the presence of Barbara Steele in dual roles as nice girl and sinister doppelgänger had become something of a miniature sub-genre of its own by the time this splendid effort from peplum specialist Mario Caiano came around. The actress is fantastic in both roles, but it is her appearance as the vengeful ghost of Muriel at the film's climax that endures as the most iconic. The minuscule but perfectly formed cast also includes Eurocult faves Paul Muller and Helga Liné as the scheming lovers who plot to drive Barbara-in-blonde-wig insane, before upping the stakes to more murder.
Great location work, superbly crisp black and white photography from Enzo Barboni and a powerfully melodramatic score from maestro Morricone, his first in the horror genre, inject a huge dose of atmosphere into a tale bookended by acts of shocking violence. That the plot is full of holes is of little consequence to the overall effect. Equally well known as Nightmare Castle and The Faceless Monster, the film easily ranks as one of the best of the non-Bava 60s Gothics, but beware of hideously truncated versions clocking in below 100 minutes.