The Loreley's Grasp is a 1973 Spanish horror film written and directed by Amando de Ossorio, and starring Tony Kendall, and Helga Liné. The film centers on a series of horrific murders in a German town by the Rhine river perpetrated by a deadly water spirit known as the Lorelei.

Plot

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.