Mercy is an exile from heaven with shattered memories of who she used to be. She's doomed to "wake" repeatedly on earth in a new body, each time assuming a new life. During the day she survives in the human world on instinct and at night her dreams are haunted by her lost love, who pleads with her to find him. But this time is different. When Mercy wakes up she meets Ryan, an eighteen-year-old reeling from the loss of his twin sister, Lauren, who was kidnapped two years ago. Only Mercy and Ryan believe his sister is still alive.