Eighteen-year-old Tally is absolutely sure of everything: her genius, the love of her adoptive family, the loyalty of her best friend, Shane, and her future career as a Nobel prize-winning astronomer. There's no room in her tidy world for heartbreak or uncertainty --- or the charismatic, troubled mother who abandoned her soon after she was born. But when a sudden discovery upends her fiercely ordered world, Tally sets out on an unexpected quest to seek out the reclusive musician who may hold the key to her past --- and instead finds Maddy, an enigmatic and beautiful girl who will unlock the door to her future. 

Maia is a teenage piano prodigy and dutiful daughter, imprisoned in the oppressive silence of her adoptive parents' house. Cass is a street rat, witch, and runaway. When a chance encounter brings the two girls together, an unlikely friendship blossoms that will soon change the course of both their lives. But Cass didn't reckon on Jason, the hypnotic blue-eyed rocker who'd capture Maia's heart as soon as Cass set her free--and Cass isn't the only one who's noticed Maia's extraordinary gifts.