S1, E16: Beaver and Wally have been late to school every day because Lumpy Rutherford terrorizes them. Ward tells the boys how he once built a 'bully trap' which shamed his bully into leaving him alone. The boys do the same thing to Lumpy, only he isn't the one who learns his lesson; Lumpy's father is the one who gets hurt and the boys have to confess what they have done.