During a New Year's Eve party just before Oona Lockhart turns nineteen, she ponders her future choices--whether to stay with her boyfriend and band in Brooklyn or leave for London to study economics. As the ball drops, she's transported into the future life of her fifty-one-year-old self. And each year thereafter on December thirty-first, Oona travels back and forward to various parts of her life in the future where she learns about living in the moment and the consequences of past decisions.