“It is a study of the psychopathologies of perversions,” co-director Federico Sanchez says in the press notes for Eternal, which is certainly one way to rationalize a trashy lesbian vampire flick. Tame and cheesy even by the modest standards of the genre, Eternal needs all the intellectual trappings it can find. The opening credits assure us that the story is “inspired by true events,” which in this case means that one of the main characters is Erszebet Bathory, a 16th-century Hungarian countess apparently famous for slaughtering young maids. Eternal finds her—now Elizabeth (Caroline Néron)—at home in modern Montreal, extolling her supernatural Rottweiler and luring closeted women to her gated mansion, where nudity-deficient intercourse serves as a prelude to bloodletting. Unfortunately, she offs the wife of a sleazebag detective (Daniel Day-Lewis look-alike Conrad Pla), who nevertheless finds himself drawn to his suspect’s Basic Instinct allure. This is the kind of movie where a character jokes that she’ll “probably be dead when you get back” and we’re supposed to be startled when the premonition proves accurate. Despite pretensions of significance (a masked orgy is shamelessly pilfered from Eyes Wide Shut), Eternal won’t even last on late-night cable.