"Dear Diary. Today I'm going to kill her. Love, Rose." When Rose discovers her troubled past splashed across the pages of a bestselling book, she knows her carefully constructed life is about to unravel. The author, Emily Harper, claims the story is fiction, but Rose knows better. Desperate to find out how Emily discovered her deepest secrets, Rose ingratiates herself into the author's life, posing as an eager assistant and adoring fan. But as Rose gets closer to the truth, long-buried memories resurface. Slowly, the horrifying events of her teenage years come into focus, revealing that sometimes, the people you trust the most are the ones you should be most afraid of.