Invisible aliens in a tiny flying saucer come to Earth looking for heroin. They land on top of a New York apartment inhabited by a drug dealer and her female, androgynous, bisexual nymphomaniac lover, a fashion model. The aliens soon find the human pheromones created in the brain during orgasm preferable to heroin, and the model's casual sex partners begin to disappear.
Alice is a withdrawn 12-year-old who lives with her mother and her younger sister, Karen, who gets most of the attention from her mother, leaving Alice out of the spotlight. But when Karen is found brutally murdered in a church, suspicions start to turn toward Alice. But could a 12-year-old girl really be capable of such savagery?