Plucky pair Winnie and Miss Drake are traveling back in time to the 1915 San Francisco World’s Fair. Waiting in the past are Winnie’s great-grandfather Caleb, Laura Ingalls Wilder, and a centuries-old mystery: Who stole the Heart of Kubera necklace? Despite the excitement, Winnie’s only wish is to lose Rowan, an unusual boy who has the annoying habit of showing up at inconvenient times. But the wise Miss Drake knows her pet Winnie should be careful what she wishes for—especially when her wish-granting souvenirs follow them home.