Here's the description from Amazon:
Strange, sleepy Rogerson, with his long brown dreads and brilliant green eyes, had seemed to Caitlin to be an open door. With him she could be anybody, not just the second-rate shadow of her older sister, Cass. But now she is drowning in the vacuum Cass left behind when she turned her back on her family's expectations by running off with a boyfriend. Caitlin wanders in a dream land of drugs and a nightmare of Rogerson's sudden fists, lost in her search for herself.
Why do so many girls allow themselves to get into abusive relationships--and what keeps them there? In this riveting novel, Sarah Dessen searches for understanding and answers. Caught in a trap that is baited with love and need, Caitlin must frantically manage her every action to avoid being hit by the hands that once seemed so gentle. All around her are women who care--best friends, mother, sister, mentor--but shame keeps her from confiding in any of them, especially Cass, her brilliant older sister, whose own flight from home had seemed to point the way.