In his BBC documentary series A History of Horror, Mark Gatiss referred to this film, along with Witchfinder General and The Wicker Man, as the prime example of a short-lived subgenre he called folk horror.

It’s directed by Piers Haggard, who also was behind The Quatermass Conclusion, The Fiendish Plot of Dr. Fu Manchu and Venom. He’s also the great-great-nephew of H. Rider Haggard, the creator of Allan Quartermain.

Robert Wynne-Simmons was hired to write the story, which was inspired by the modern-day Manson Family and Mary Bell child murders.

In the early 18th century, Ralph Gower (Barry Andrews, Dracula Has Risen from His Grave) uncovers a one-eyed skill covered with fur while plowing his fields. He asks the judge (Patrick Wymark, Dr. Syn, Alias the Scarecrow) to look at it, but it’s gone missing, and his fears are ridiculous.

Peter Edmonton brings his fiancee, Rosalind Barton (Tamara Ustinov, Blood from the Mummy’s Tomb), to meet his aunt, Mistress Banham. Banham disapproves of the coupling and demands that Rosalind sleep in an attic room. After screaming throughout the night, she soon gets ill, and the judge commits her. As she’s led away, Peter discovers she has a claw instead of a hand.

Claws show up all over this — hidden in fields to be found by children and attacking Peter inside the cursed room, causing him to sever his hand. The judge leaves behind the town for London but promises to return. He places Squire Middleton (James Hayter, The 39 Steps) in charge.

One of the children who found the claw, Mark, is lured out by his classmates and killed in a ritual game by the leader of a new cult, Angel Blake (Linda Hayden, Madhouse, Queen Kong). She even tries to seduce Fallowfield (Anthony Ainley, the Master from Dr. Who) and tells him that Mark had the devil inside him, which needed to be cut out. Her group also has a Black Mass inside a ruined church where they attack Mark’s sister Cathy (Wendy Padbury, companion Zoe on Dr. Who). They ritualistically assault and murder her before tearing the fur from her skin.

Of course, it’s not long before all hell quite literally breaks loose, with insane children raising Satan himself from the Great Beyond and Ralph growing fur on his leg, marking him for death. This movie is…well, there’s nothing else quite like it. I can see why it had a limited audience for years; it’s so dark and unforgiving.

“It never made much money,” said Haggard. “It wasn’t a hit. From the very beginning, it had a minority appeal. A few people absolutely loved it, but the audiences didn’t turn out for it.”

While Satan’s Skin was the original title, you must give it to American International Pictures’ Samuel Z. Arkoff, who created the film’s title.