All is Nat lost

"Nat's class is visiting Philadelphia, PA, for a tour of art, culture, and history! After struggling to get her mom to sign her permission slip, Nat finally gets her parents' blessing to go. But amid spats between classmates, lost possessions, and unannounced bathroom breaks, Nat and her friend Flo get separated from the group! Can they find their way back or will be stuck in Philly?"--.