On a technicality, Wally is able to convince his parents to let him throw a party on Saturday night. Everyone in the house, wanting it to be a good time for all, are excited in preparation, including Beaver, despite he having to do no prep work. Beaver's attitude changes when he learns from Wally that he isn't invited to the party, which, although they don't totally agree, is supported by their parents. Upon this news, Beaver feels like the mad but forgotten member of the household. In order for Beaver to get back at Wally but still not totally ruin the party, Gilbert suggests that Beaver plays some gags, like putting fake cheese in the sandwiches and rubber spiders in the curtains, which Beaver does decide to do. On the day of the party, Wally, on a suggestion from his parents, has a change of heart and decides to let Beaver come to the party. Beaver's excitement at being able to attend turns to panic when he finds that undoing the gags is a little more difficult than putting them in place.
—Huggo