7Elena, 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.