Fifteen-year-old Calli has almost everything she could want in life—two loving moms, a good-looking boyfriend, and a best friend who has always been there for support. An only child, Calli is excited when her parents announce that they want to foster a girl named Cherish. Unfortunately, having a new sister is not at all what Calli expected. Cherish lies, steals, kisses Calli’s boyfriend, and seems to get away with just about everything. Tired of being pushed around and determined to get even, Calli decides to take matters into her own hands. But her plan for revenge goes horribly awry. Calli ends up isolating herself from her moms, her boyfriend, and even her best friend, while she wrestles with her guilt. She is desperate for a chance to make amends, but finds some relationships are easier to repair than others.