By the time she's two years old, Violet Van Winkle can engineer nearly any appliance in the house. And by eight she's building elaborate flying machines from scratch - mind-boggling contraptions such as the Tubbubbler, the Bicycopter, and the Wing-a-ma-jig. The kids at school tease her, but they have no idea what she's capable of. Maybe she could earn their respect by winning the blue ribbon in the upcoming Air Show. Or maybe something even better will happen - something involving her best-ever invention, a Boy Scout troop in peril, and even the mayor himself!