Mr. Cassidy, teacher of Room 8, which houses the 19 boys who are the Sads and the Bads at St. Boniface School. These boys, who "have the boredom thresholds of brain-damaged gnats," choose as their science project The Great Flour Baby Experiment: each takes full-time responsibility for a six lb. bag of white flour, with instructions to keep it dry, safe from harm, and absolutely mud-free. All rapidly lose patience with the project-all, that is, but Simon Martin, who goes "moon-eyed" over his flour baby. Simon not only learns of the immense yet often tedious responsibilities of parenthood, but also comes to a deeper understanding of his own father's absence and an appreciation of his mother's plight as a single parent.