Visitors is an original novel based on the U.S. television series Buffy.
In "Visitors", Buffy is the distinct impression that she's being stalked by a demon that emits a high pitched giggle. After discussion and research with Giles, they discover that Buffy's being stalked by a 'korred'; a nasty hairy beast that feeds off of peoples life forces by making them dance until they die to his magical song. The korred is particularly attracted to Buffy because of her Slayer aura. Buffy must stop to korred before he makes her dance to her death. Visitors on Wikipedia