The Uncertainty Principle

God seems to be playing matchmaker when he encourages Joan to ask a school ruffian to the winter semi formal. Joan's date choice doesn't sit well with her parents, however, especially after Will learns the boy has a juvenile record. Will's also digging up some distressing information about his predecessor as chief of police, who, it turns out, is still cashing a paycheck under another person's name. Meanwhile, Luke looks forward to entering this year's science fair with Grace Polk as his partner.