Roller derby players, to your positions! Best friends Kenzie "Kenzilla" Ellington and Shelly "Bomb Shell" Baum are counting down the days to their roller derby debut. It looks like their dream is coming true when Austin's city league announces a junior league. But there's a catch. To try out together, the Dynamic Duo will have to form a team of five players ... in just one week! As they start convincing other girls that roller derby is the coolest thing on wheels, Kenzie has second thoughts. Why is Shelly acting like everyone's best friend? Isn't she supposed to be Kenzie's best friend? And things get really awkward when Shelly recruits Kenzie's neighbor (and secret crush!) for the team. With lots of humor and an authentic middle-grade voice, the first book of this empowering series follows Kenzie, Shelly, and the rest of the Derby Daredevils as they learn how to fall—and get back up again.