Home from college, Megan spends her days in her east-wing room of her parents' palatial estate overlooking the pool house where her sister has taken up residence. Her sister Ashley spends her days wildly bucking convention, bringing home a bevy of female lovers, each one more dangerous than the last, and making love to them by the pool—in plain view of her sister, their conservative parents, and their bewildered staff. Ashley stays out all hours, goes places that she doesn't tell anyone about, and keeps secrets that only she knows. Then one night, Ashley is murdered, and when the case grows cold, Megan immerses herself in her sister's underground life in order to find out who killed her and why. She starts by finding Ashley's diary and begins a sexual odyssey of her own. Will she find the answers she seeks, or will her growing relationship with one of Ash's exes blind her to the real truth?