Twelve-year-old Caleb is shorter, frailer, and more protected than most kids his age. That's because he has cystic fibrosis, a diagnosis meaning lungs that fill with mucus and a shortened lifespan. Caleb tries not to let his disorder define him, but it can be hard with an overprotective mom and a perfect big brother. Then Caleb meets Kit, a vibrant, independent, and free girl, and his world changes instantly. Kit reads Caleb's palm and tells him they are destined to become friends. She calls birds down from the sky and turns every day into an adventure. Her magic is contagious, making Caleb question the rules and order in his life. But being Kit's friend means embracing deception and danger, and soon Caleb will have to decide if his friendship with Kit is really what's best for him, or her.