Forget the claim that this was based on a story by Peter Bryan. No, this is director Antonio Margheriti and writer Giovanni Simonelli coming together to make a giallo in the wake of the animal films of Argento but getting to having an orangutan get involved way before Dario did that (yes, I get that this movie has a gorilla suit, but the dialogue calls it an orangutan).

Dragonstone Castle is a crazy place filled with crazy people and that’s just the way I want it to be. It’s also where Corringa (Jane Birkin, who was in Blowup and Kaleidoscope but may be best known for her marriage and work with Serge Gainsbourg, including the song “Je t’aime… moi non plus,” a song written for Brigitte Bardot, whose husband Gunter Sachs demanded that the version she sang on not be released. Gainsbourg claimed it was an “anti-fuck” song about the desperation and impossibility of physical love, but it sure sounds like — and it was rumored — that Gainsbourg and Birkin are making love while recording lyrics which include phrases such as, “Je vais et je viens, entre tes reins” or “I go and I come, between your loins” and “Tu es la vague, moi l’île nue” or “You are the wave, me the naked island.”) has just arrived, seemingly moments after someone has been killed by a black-gloved killer with a razor.

Corringa used to spend summers there with her mother, Lady Alicia (Dana Ghia). She reunites with her and her aunt, Lady Mary MacGrieff (Françoise Christophe), who is rich in title only, having lost much of her money, as many aristocrats did in the late 60s. There’s also a priest (Venantino Venatni), Dr. Franz (Anton Diffring), a French teacher named Suzanna (Doris Kunstmann) and Lord James MacGrieff (Hiram Keller) who has the same name as the orangutan, which is not confusing at all.

And oh yes, an orange cat who likes to watch people die.

Mere seconds after her first dinner in the house, Corringa finds that her mother has been suffocated, possibly by Lord James, who she finds in a passage under the castle after following the orange cat. If that’s not enough, the cat also jumps on her mother’s coffin during her funeral, a sign that someone is a vampire, and to make that even more true, the legend says that if one MacGrieff kills another, they become a fanged blood drinking undead killing machine.

If you’re wondering when Luciano Pigozzi shows up in this Antonio Margheriti film, that would be now, but he’s soon killed by the razor-using madman. Or woman, right? Corringa now dreams of that her mother is a vampire and the cat wakes her at night. She’s soon sleeping with James — oh Italian horror families — and someone unlocks the simian beast from his cage. Also, the priest and the French teacher are sleeping together, but he’s soon also slashed. And Lady Alicia’s coffin is empty.

Ah, so many twists and turns. That’s why Margheriti is so good at movies like this, which flirt with horror and the gothic as well as giallo. Plus Serge Gainsbourg shows up as a police officer.

The Riz Ortolani soundtrack is almost a greatest hits of Margheriti’s horror films. You can hear bits of The Virgin of Nuremberg and Castle of Blood.