Description
In a small German village near the Rhine river, a nearby boarding school is plagued by a series of grisly murders of its female students every full moon. Locals in the area blame the killings on a legendary water spirit known as The Lorelei, which is said to reside in a grotto beneath the Rhine river, and transform from a beautiful woman into a reptilian monster that hungers for human blood every full moon. As the murders continue, an experienced hunter named Sigurd is hired by boarding school teacher Elke Ackerman to guard the school. Sigurd sets a 9 o clock curfew on all the boarding school\'s residents, during which all the windows and doors are to be locked and no one is to leave the school grounds during that time.
One night while patrolling the school grounds, Sigurd encounters a mysterious cloaked woman who runs off after noticing him. Later that night, while bathing in a nearby lake, Sigurd once again encounters the mysterious woman but is unable to catch her. In his search for the woman, he encounters Professor Von Lander who has been studying the creature for some time. Taking him back to his lab, Lander reveals to Sigurd that the Lorelei can transform into a monster by the light of the full moon. Lander also reveals that he made an irradiated dagger that is capable of and reverting the Lorelei back to its human form. Meanwhile a small hunting party is slaughtered by the creature. It\'s revealed that the mysterious woman stalking Sigurd is the Lorelei, however Sigurd has fallen under Lorelei\'s spell and refuses to believe that she\'s responsible for the murders. While under Lorelei\'s influence, Sigurd accidentally reveals Von Lander\'s involvement.
Lorelei, along with her human servant Alberic, murder Von Lander and destroy his research in an effort to prevent anyone from stopping her. Sigurd, who has now come to believe that Lorelei is somehow responsible for the killings, later discovers an underwater cave while diving, which leads to a hidden temple inhabited by Lorelei, Alberic, and a hoard of feral women. Sigurd is soon discovered and captured. While Sigurd is restrained, a vengeance-driven Lorelei heads to the boarding school to murder Elke, after discovering Sigurd\'s feelings for her. One of the feral women manages to help Sigurd, freeing him and perishing along with the temple\'s inhabitants as the dynamite Sigurd had previously set goes off.
Arriving at the boarding house with the irradiated dagger, Sigurd manages to slay the murderous Lorelei before she is able to make Elke her next victim.