Twelve-year-old Anna Hart of Flemington, New Jersey, a student at a school for gifted children, is a genius and a kleptomaniac who insults her teachers, gets headaches when she stares at fires and flickering lights, and suffers from strange, prophetic dreams. Michaela Dupont, a piano teacher who has been watching Anna and has kept photos of her and a similar-looking girl taken in 1970, moves in next door. Then Anna sees her exact double on local TV news when a commuter plane makes a forced landing nearby, and she learns that her double, Anna Smithson, has the same family setting as hers — the child of a scientist and a musician.