Though the Mallory women are twins, nobody has ever had trouble telling them apart. Harper is a famous painter who lives in the wealthy enclave of Stone Point, and is beautiful and vivacious and dangerous. Liz is a librarian and lives a modest and quiet existence in the Mallorys' hometown of Longwood Falls.
Having been constantly compared since childhood, neither woman cares much for the other and they have not spoken in years - until a family tragedy - the death of Harper's young daughter - forces them to break their silence and confront their past. Then Liz finds herself falling in love with David Fields, a high-school teacher cum amateur astronomer with a difficult secret in his past. From his private observatory he gives her a glimpse of the mysteries of the universe - and of the heart.