Elena, Jorge, and Marcus must brave the Chicago winter in search of a vampire. In a bleak, post-Depression city, the children must not only find this creature of the night, but also find her lost locket. Will it be downtown at Marshall Fields? Or at a roller derby event? And will they find it in time to get home? Readers will find out, as they learn about the 1930s—and how to survive an encounter with the undead.