Jean Rollin improvised most of the story after losing the script on the third day of shooting the picture.
This film consists of two parts. The first (coherent) part is the original short film made by Jean Rollin. The second (incoherent) part of the film was later added by Rollin to expand the film so it could be released to theatres as a feature. That is why most of the characters who were killed in the first part are suddenly brought back to life for the second part.
Because of the events of May 1968 in Paris, French distributors, fearing for the box office, decided to freeze their activities until it went back to normal. As a result, no other new feature was released during that period apart from this one. Consequently, by lack of competitors, it became the most successful film of the month in France.
Jean Rollin said this film had a terrible reception from horror fans. "People were whistling, throwing objects at the screen. Le Scarlet, the theater where the film was shown, was once cleared by the police. It was an awful scandal, because people didn't understand the film. The film announced itself as an erotic film, because of the word 'rape,' but also as a vampire film, with the word 'vampire.' At the time, the viewers only accepted, in this genre, the Hammer vampire films. What was going off the beaten track was badly received. The moviegoers and the fans of fantastique hated my work because it has no common point with the usual films. For them, a vampire film wasn't that. The scandal was so intense that, at one time, I thought about moving to another career and leaving the cinema."
Jean Rollin's first feature length film. He would continue to use the themes of vampires, lesbianism, and the beach in other films. It was originally commissioned as a half-hour short by American producer Sam Selsky to round out a double bill alongside a French-dubbed version of 1943's Dead Men Walk. When Selsky saw what Rollin could do on a next-to-nothing budget, he gave the go-ahead to expand the short to feature length, figuring it would end up costing "twice nothing."