If She Only Knew, introduces the Cahills, a wealthy San Francisco family--rich in money, twisted secrets, and hidden agendas. Now at the center of their tangled world is Marla Cahill--a woman with no memory of who she is, what she's done, or why she could be the next to die . . .

It begins on a dark stretch of highway in northern California. Caught in a blinding glare of headlights, two vehicles swerve and crash--leaving one woman dead, and another in a coma. When the surviving woman awakens, her memory is gone and her face has been reconstructed. Her family tells her that her name is Marla Cahill--but they're all strangers to her.

Recuperating in her isolated San Francisco mansion, Marla waits for something to trigger recognition. Yet the only thing she's left with is the unshakable feeling that she is not who everyone says she is, and that something is very, very wrong. Marla knows her life isn't just different--it's in danger. And as her fear builds, a killer waits for the perfect moment to strike--the moment Marla remembers . . .