Marge invites Grampa and two other octogenarians to live at the Simpsons' house after the Retirement Castle is closed for health violations, but she quickly becomes frustrated with Homer when he starts embracing the "old person lifestyle." Meanwhile, at Springfield Elementary, Bart defends Nelson's affinity for hand-me-down underwear, leading Nelson to befriend Bart. Blackboard 'My Dad's already drunk for St. Patrick's'.