Jerry's parents Helen and Morty are visiting again, to attend Helen's cousin Manya's 50th wedding anniversary. Jerry returns triumphantly from a softball game, where his winning play advanced the team to the championship, and declares it the greatest moment of his life. Helen obliges him to attend the anniversary, and he, in turn, is obliged to bring Elaine along since they have already made plans.
Kramer boasts that he will replace all the furniture in his apartment with stair-like "levels" made of lumber and carpeted with pillows. Jerry confidently wagers that this will never happen, and Kramer bets him dinner, giving himself until the end of the month.
At the anniversary dinner, Elaine quietly suffers sitting at the diminutive kids' table. Jerry, despite anticipating that Uncle Leo would accost him as always with cousin Jeffrey's exploits in the Parks and Recreation department, cannot escape Leo's arm-lock. Hearing that a relative is marrying a racehorse owner, Jerry and Elaine mock the ostentation of horse and pony ownership. Jerry reviles all kids who grew up owning ponies, not realizing that he tarred Manya with the same brush. Manya proudly retorts that, growing up in her native Poland, ponies were common to all. Manya indignantly retires from dinner as Jerry backpedals, then makes prolonged excuses for his ignorance.
Kramer gives up his project before even starting—but also uses this as his excuse to welsh on the bet. Uncle Leo phones with news of Manya's death, forcing Jerry to call his parents back as they leave for the airport. Despite nobody calling him out, Jerry denies causing Manya's death and disowns any obligation to attend the funeral. With the funeral overlapping his championship game, Elaine obliges him to attend. In contrast, George obliges him to go to the game, having no other left fielder on their team. They contemplate whether the dead attend funerals "in spirit", when they could instead transcend the material world.
At the funeral, Jerry is humbled by the eulogizer celebrating the memory of Manya's pony, the "pride of Kraków". Manya's husband, Isaac, is unruffled by the pony remark, so Elaine aggressively asks to take over his and Manya's rent-controlled apartment. After getting sidetracked on his own move to Phoenix, Isaac finally answers that cousin Jeffrey is moving in. Morty, chafing at giving up his cheap, non-refundable return airfare, harasses his medical school-graduate nephew for a fraudulent doctor's note to avoid paying the full price for fares.
Sudden rain delays the championship game, giving Jerry a reprieve. However, in the game, he repeatedly bungles his base running and even gets picked off. As Jerry declares this the worst moment of his life, Elaine wonders if Manya cursed his plays in revenge.