For generations, the Beaumont family has harbored a secret. They each possess a “savvy”—a special power that strikes when they turn thirteen. Grandpa Bomba moves mountains, Mibs’s older brothers create hurricanes and spark electricity…and now it’s the eve of Mibs’s big day. As if waiting for her savvy to show up wasn’t hard enough, Mibs’s family gets scary news two days before her birthday: Poppa has been in a terrible accident. With the hope that her new power will save Poppa, Mibs sneaks onto a salesman’s bus bound for the hospital… only to find the bus heading in the opposite direction. Suddenly, Mibs finds herself on an unforgettable odyssey that will force her to make sense of growing up—and of other people, who might also have a few secrets hidden just beneath the skin.