Barely surviving in the barren wasteland that was once California, orphans Leandro Rivera, thirteen, and his sister, Gabi, nine, plot to leave the harsh society of the Pocatelans, who use threats and harsh punishments to keep Cascabeles like them subjugated. When they hatch a plan to leave, Leandro takes the fall for Gabi when she steals a strawberry and gets caught. Instead of banishment, Leandro's consciousness is placed into a hummingbird drone and he's given the task to find a missing person. But when Leandro ventures out beyond the city, what he discovers could change his and Gabi's lives forever.