Mikey and Margalo, the redoubtable Bad Girls, are back for ninth grade and a new set of conflicts with both peers and authority figures. When unconventional Margalo, glad to be a behind-the-scenes tech in the Drama Club, discovers that someone has stolen her wages during rehearsal, the teacher advises her not to rock the boat. When Mikey, working her way up the tennis-team ladder, refuses to cheat on line calls, the coach throws her off the team. Adults having failed them, it’s up to the Bad Girls to set the world right. Voigt’s narrative verges on the savage at times, but as always, pegs the sociopolitical psychodynamics of the school setting absolutely on the money. Even as Mikey and Margalo struggle with either unresponsive or hostile adults, they find they’ve achieved a reputation as “fixers,” to whom other students apply for help. Subplots pad the whole, but do not advance plot or character development—a shame in an otherwise wickedly delicious offering. (Fiction. 12+)