French director Jean Rollin worked on the storyline to for this film whilst undergoing lengthy dialysis treatment. The extra time enforced on the project results in one of his most polished work, in my view. We have Louise and Henriette (Alexandra Pic and Isabelle Taboul), two girls (sisters possibly) who are blind by day and fully sighted vampires by night. The reason seems to be that they are Aztec Gods, or descendants thereof, and as such, can never really die.
Much is made of their night-time activities. Their blue-tinged journeys are either seen as sinister hunts or the mischievous naughtiness of two young scamps. This balance between schoolgirl killer and playful sinner is achieved very well. The actresses exude an other-wordly charm that makes them strangely appealing, despite their misdeeds.
Of course, there is the opportunity to pick out plot holes - why did the girls kill the good Dr Dennery after he provided them with a home, and whom they had just convinced of their good intentions? And why did the passer-by in the cemetery, after noticing they were not really blind, assume them to be demons from hell and threaten to beat them with a stick? – but why bother? It would, as always, be like trying to dissect a dream, a place where the usual rules either don’t exist, or simply don’t matter.