Sixth-grader Maple has received absolutely devastating, world-shaking news: her health class fitness test has scored her at a fifth-grade level. That's a whole grade level below where she should be. Having all her life been an overachiever--and fitness being an extremely important part of her twenty-year plan to become an astronaut like her hero Jackie Grand--Maple knows she has to fix this ASAP.

Maple and Lada decide to join the track team to improve their fitness scores, but they encounter new (and frankly unpleasant) variables like changing in locker rooms and periods. And when it turns out Lada is good at track, and her competitive spirit starts to change her, Maple is sent into a tailspin over her own performance and what it means if she can't--literally and figuratively--keep up with her classmates.