In an awkward fusion of fantasy and cautionary tale, a predictable story about a 14-year-old girl's haunted attic becomes a lesson about the wily ways of child pornographers. Athletic, fashion-conscious and socially inept, Anna, the narrator, is lonely when her parents relocate to a quaint Vermont town to run an upscale inn. Her first real friend is Roxy, who became a ghost after a botched abortion in the 19th century. The two look strangely alike. Is Roxy just a projection of Anna's psyche? It seems so when the ghost warns naive Anna against being photographed by Tony, a handsome lech. After Tony feeds Anna a hash brownie and tries to coerce her into making a naked aerobics video, Roxy-in the novel's hasty climactic scene-pushes him off a cliff. Or was it Anna? A zestful cast of supporting characters (a one-handed basketball player, a feminist painter, therapists who are also UFO fanatics, and ""the most famous rock and roll duo in the world"") is sadly wasted in favor of shallow drama. Showing little of the dark wit and insight of his The Grounding of Group 6, Thompson glides over serious emotions with teen-speak: after Tony's death and her own near-victimization, Anna is ""really bummed, and tired, and confused."" Most readers will feel the same. Ages 10-14. (Apr.) FYI: Also in April, The Grounding of Group 6 will appear for the first time in a hardcover edition ($16.95, -5058-X).