It stars Peter Cushing, Christopher Lee, Barbara Shelley and Richard Pasco. The film was photographed by Michael Reed, and designed by Bernard Robinson. For the score James Bernard combined a soprano with a little-known electronic instrument called the Novachord. The film marks one of the few occasions when Hammer turned toGreek mythology for inspiration; this time it is the legend of the Gorgon that is respun for the Hammer audiences.
The year is 1910. In the rural German village of Vandorf, seven murders have been committed within the past five years, each victim having been petrified into a stone figure. Rather than investigate it, the local authorities dismiss the murders for fear of a local legend having come true. When a local girl becomes the latest victim and her suicidal lover made the scapegoat, the father of the condemned man decides to investigate and discovers that the cause of the petrifying deaths is a phantom. The very last of the snake-haired Gorgon sisters haunts the local castle and turns victims to stone during the full moon.
- Christopher Lee as Professor Karl Meister
- Peter Cushing as Dr. Namaroff
- Richard Pasco as Paul Heitz
- Barbara Shelley as Carla Hoffman/Magera
- Michael Goodliffe as Professor Jules Heitz
- Patrick Troughton as Inspector Kanof
- Joseph O'Conor as The Coroner
- Prudence Hyman as Gorgon body
- Jack Watson as Ratoff
- Redmond Phillips as Hans
- Jeremy Longhurst as Bruno Heitz
- Toni Gilpin as Sascha Cass
- Joyce Hemson as Martha
- Alister Williamson as Janus Cass
- Michael Peake as Constable
The Gorgon sisters of Greek legend were named Stheno, Euryale, and Medusa. In the film, they are referred to as Tisiphone, Megara, and Medusa. One character theorizes the Gorgon on the loose to be Megara.
The film was adapted into a 10-page comic strip for the September 1977 issue of the magazine House of Hammer (volume 1, # 12, published by Top Sellers Limited). It was drawn by Alberto Cuyas from a script by Scott Goodall.
In North America, the film was released in 2008 along with three other Hammer horror films (The Curse of the Mummy's Tomb, The Two Faces of Dr. Jekyll and Taste of Fear) on the 2-DVD set Icons of Horror Collection: Hammer Films (ASIN: B001B9ZVVC), from Sony Pictures Home Entertainment. It is available in the UK as a single disc from the same company.