Lisa feels that her relationship with her father will never be close, and she develops stress-induced stomach pains; Marge inadvertently knocks out Milhouse.
Homer takes Bart with him on a cross-country delivery on behalf of a trucker who died before completing it; Marge and Lisa experience problems with their new novelty doorbell.
Lisa is invited to join the Springfield chapter of MENSA and after Mayor Quimby flees, the group ends up running the city. Meanwhile, Homer poses for a series of erotic photos.