Can she perform the vault of her life to save her loved ones—and herself?

Sixteen-year-old gymnast Elizabeth Arlington doesn't care that her mother is older than the other girls' moms or that she doesn't look anything like her parents. She has too much to worry about like her body changing and how all of a sudden the balance beam is not as easy as it used to be. But when she makes a discovery that throws her entire identity into question, she turns to her ex-best friend Zach, who suggests a way for her to find the answers her mother won't give her: a time machine they found in an abandoned house.

As Elizabeth catapults through time, she encounters a mysterious abandoned child, an elite gymnast preparing for Olympic Trials, and an enigmatic woman who seems to know more than she's revealing. Then when a thief makes off with an identical time machine, Elizabeth finds herself on a race to stop the thief before the world as she knows it—and her future—are destroyed.