Sixth grader Lucy loves fantasy novels and is brand-new to middle school. GiGi is the undisputed queen bee of eighth grade (as well as everything else she does). They've only got one thing in common: fencing. Oh, and they're sisters. They never got along super well, but ever since their dad died, it seems like they're always at each other's throats.

When GiGi humiliates Lucy in the cafeteria on the first day of school, Lucy snaps and challenges GiGi to a duel with high sisterly stakes. If GiGi wins, Lucy promises to stay out of GiGi's way; if Lucy wins, GiGi will stop teasing Lucy for good. But after their scene in the cafeteria, both girls are on thin ice with the principal and their mom. Lucy stopped practicing fencing after their fencer dad died and will have to get back to fighting form in secret or she'll be in big trouble. And GiGi must behave perfectly or risk getting kicked off the fencing team.

As the clock ticks down to the girls' fencing bout, the anticipation grows. Their school is divided into GiGi and Lucy factions, complete with t-shirts declaring kids' allegiances. Both sisters are determined to triumph. But will winning the duel mean fracturing their family even further?