It's 1935 and 11-year-old Lewis Carter is homeless and hungry. His scientist father has disappeared and the landlady put him out on the street; now he just has his wits and his dad's "recipe" - a little something Lewis pulled together from his father's research. The Recipe is a mixture that, when activated, causes a flash and leaves behind a lingering stink. When he needs to steal some food, he uses the Recipe, leading the newspapers and wagging tongues to make up stories about the villainous Flash Gang. It's all good for Lewis: who would suspect the quiet, asthmatic kid? Someone knows something, though, because Lewis is kidnapped and his Recipe is taken from him; rescued by a tutu-wearing girl named Pearl Alice Clavell, who seems to think she's living in a serial movie, Lewis has to figure out what really happened to his father, and what information Pearl may have that can help him. This first entry into a new series reads like a classic adventure serial, with fast-paced banter between hero and heroine and exaggerated baddies aplenty. The Depression-era Pittsburgh setting gives texture to the overall story, and the science-based subplot makes this a fun suggestion for STEM/STEAM reading lists.