For Tara Krishnan, navigating Brierly, the academically rigorous prep school she attends on scholarship, feels overwhelming and impossible. Her junior year begins in the wake of a startling discovery: A message from an alternate Earth, light years away, is intercepted by NASA. This means that on another planet, there is another version of Tara, a Tara who could be living better, burning brighter, because of tiny differences in her choices.