Rachel Blum and Andy Landis are just eight years old when they meet one night in an ER waiting room. Born with a congenital heart defect, Rachel is a veteran of hospitals, and she's intrigued by the boy who shows up alone with a broken arm. He tells her his name. She tells him a story. After Andy's taken back to a doctor and Rachel's sent back to her bed, they think they'll never see each other again. Rachel grows up in an affluent Florida suburb, the popular and protected daughter of two doting parents. Andy grows up poor in Philadelphia with a single mom and a rare talent for running. Yet, over the next three decades, Andy and Rachel will meet again and again-linked by chance, history, and the memory of the first time they met, a night that changed the course of both of their lives.