Spring has sprung in River Heights, along with a brand-new cupcake café! The Lucky Ladybug, run by twin bakers and celebrities Gwendolyn and Carolyn Porter, is the talk of the town. Nancy, Bess, and George can't wait to taste some of the delicious cupcakes!

But on the day of the opening, the ceremony--and the cupcakes--are ruined by hundreds of live ladybugs that invade the store. It's up to Nancy and the Clue Crew to get to the bottom of this cupcake disaster before the Lucky Lady Bug Cupcake Café has to close for good!