There are so many moments Ruby Wright wishes she could change. The moment her dad uprooted her from California to live in backwoods Ohio with their new stepfamily. The moment she moved away without telling her best friend George she loved him. The moment a car accident ended her mother's life.

But no one can rewrite time. At least, that's what physics-obsessed Ruby believes.

Then she stumbles upon a lightning-powered tree—a doorway to a series of parallel universes. How many possible worlds will Ruby have to explore to find the one with the perfect combination of people, relationships, and experiences? And is she willing to risk everything she has to get back what she has lost?

With a deft blend of science and heart, Cristin Bishara's thought-provoking debut novel explored the laws of time and space...and the even more mysterious nature of love and loss.