Two worlds collide when 12-year-old Poppy, a skilled pickpocket working the streets of 1870s Chicago, meets 13-year-old Justin Butterworth, a prominent jeweler’s son. Justin’s sister warns, “Be careful. . . . You don’t know where this friendship with Poppy might lead you.” Yet with the help of Justin’s goat, Ticktock, he and Poppy soon become friends. Neither character has it easy: Justin is jealous of his older brother, Charlie, the next in line to run their father’s business, and Poppy’s “caretaker,” a Fagin-like character, forces Poppy to make a wax impression of the key to the Butterworth’s store in hopes of robbing it. Narrated in alternating chapters by both Poppy and Justin, the story follows their struggles and ends with their suspenseful escape from the Great Chicago Fire. Although the dialogue doesn’t always ring true, and the situations occasionally seem contrived, Harlow has done her research about the details of the fire and effectively touches on class issues and the economic disparity of the time.