Chelsea Smythe, 17, is working in her father's office against her will the summer after her stepmother, Diane, leaves him. As a punishment for talking to her friend Amber during office hours, Chelsea must work down in the gritty basement of Smythe Towers. There she discovers a device that allows her to eavesdrop on phone conversations all over the building. With it she hears a mysterious conversation that leads her to discover Diane's dead body in an isolated cave. She reports her findings to the police, who at first don't believe her and then accuse her father of murder. Trying to clear Mr. Smythe, Chelsea goes back to Smythe Towers, although she has been warned against it by the killer and the police, and she and Amber discover that Diane had been involved in insurance fraud along with a Dr. Marcroft. Dr. Marcroft appears and plans an elaborate ending for the two teens, but, thanks to Chelsea's one stroke of ingenuity, his scheme is foiled, Mr. Smythe is exonerated, and Chelsea and her father make up their differences. Ferguson (Stardust, 1993, etc.) writes with a contemporary voice that will appeal to young teens, but her mystery is nothing more than the misconceptions and misinformation of a pretty clueless heroine. Chelsea comes off as reckless rather than intrepid, which wears on the readers sympathy until it is all but gone.