After Homer loses his license for DUI, Marge pressures him to give up beer for a month; Lisa attempts to prove that Bart is less intelligent than a hamster.
Homer gets barred from driving and forced to attend Alcoholics Anonymous meetings. He decides to use Lisa's bike but only falls off and gets bombarded with bottles from the Duff balloon. However he eventually keeps his promise to Marge to stay Duffless for thirty days and they cycle off into the sunset. Lisa proves that a hamster is more intelligent than Bart in the run up to displaying their science projects but he ultimately upstages her by flying the hamster around the class in a miniature plane.—don @ minifie-1