"Claudia isn't worried when she hears her newest baby-sitting charge, Betsy Sobak, is a big practical joker. After all, how much harm can one little girl do? Plenty. Claudia breaks her leg as a result of one of Betsy's jokes. Now Claudia is feeling like baby-sitting might be too dangerous and she's talking about quitting the club. Kristy thinks Betsy needs to be taught a lesson, and that the baby-sitters are just the ones to do it. Watch out, Betsy...

Best friends Annabelle and Tiffany risk placing all of dollkind in danger when they run away while trying to prevent Tilly from being sent back to London before they can determine if she is Annabelle's long-lost baby sister.