'The perfect thriller' Elle 'Immensely gripping' Sophie Hannah 'Gripping, creepy and very addictive!' BA Paris 'He's so handsome and clever and romantic. I just wished he hadn't forced Tilda under the water and held her there so long.' Callie loves Tilda. She's her sister, after all. And she's beautiful and successful. Tilda loves Felix. He's her husband. Successful and charismatic, he is also controlling, suspicious and, possibly, dangerous. Still, Tilda loves Felix. And Callie loves Tilda. Very, very much. So she's determined to save her. But the cost could destroy them all... Sometimes we love too much.