Twin uncles Jasper (the bad one) and Julian (the good one) are saddled with offspring they think are unsatisfactory. Wicked Jasper has seven sons who have no talent for villainy, and virtuous Julian's daughter, Prudence, shows little aptitude for being an Old Fashioned Heroine. When wicked Jasper's sons create a simpering robot named Lilly Rose Blossom (with blond ringlets, blue eyes, and a taste for paragon soup) and send it to Prudence as a gift, Prudence retaliates with the Nadger, a larcenous robot with a one-track mind. Unable to cope with these "raging robots," the children run away from home, only to meet and combine their talents to make a profitable living. Meanwhile, Jasper and Julian are having problems dealing with the robots. All comes to a satisfactory conclusion when the uncles, the robots, and the children meet in a finale of the Marx brothers variety--complete with a sobering subtext about taking responsibility for what one creates. Mahy's clever wordplay has humor and bite, and, if a bit adult, lends itself very well to reading aloud.