The various obsessions of Lizzie, Matt and Gordo are driving friends, family, teachers and themselves to distraction. Gordo is intent on winning the Science Olympics at all costs against defending champion Larry Tudgeman. Matt becomes hall monitor at his school and gets carried away with his own power, giving out citations to schoolmates by the dozen and even trying to do the same to teachers and family members. Meanwhile, after she and Miranda work on a successful volunteer project at school, Lizzie becomes an environmental warrior, a fanatic for collecting clothing and food for the homeless, and even a vegetarian! All three learn that they must put limits on their fanaticism or else their original causes will suffer as a result.