Successful author Molly Hunt, the adopted daughter of Long Island parents, is stunned when a handsome man she meets in her publisher's office makes a startling declaration: that he is about to marry her twin sister. Molly soon discovers that she is actually the long-lost child of the wealthy Mountfort family of Charleston, South Carolina. Eager to solve the puzzle of her birth, Molly begins a fateful journey south.

At the historic family plantation, she meets her beautiful twin Amelia, their reclusive mother, and a cast of intriguing yet disturbing characters who both question her identity and, in their way, confirm it. Nevertheless, her arrival has set in motion a series of strange and frightening events, and in the intoxicating, magnolia-scented world of Molly's original family, haunting memories of an unsolved murder threaten the family's very existence—as well as her own.