Marge's crusade to get the family dog in better shape leads to her entering Santa's Little Helper in canine agility competitions and a trip to the National Dog Show in Philadelphia. There, Marge and Homer suddenly find themselves mixed up in a historical conspiracy adventure. Homer strikes up an unlikely friendship with Kirk Van Houten, which leads to them launching a successful business together. When Kirk's darkest secrets are revealed, Homer has to choose between his family and his fortune.