Mr. Burns attends the annual Billionaires' Retreat, where he wins the fictional Austin Celtics pro basketball team in a poker game against the Rich Texan. After witnessing the antics of Mark Cuban at a Dallas Mavericks game, Burns tries to win over Springfield basketball fans with his own antics. Burns fails miserably, and decides to build a luxurious sports arena. Meanwhile, Jimbo, Dolph, and Kearney dare Bart to prank the second graders by hitting a beehive with his slingshot. Lisa discovers, however, the bees that should be in the hive are dead. Willy explains the bees are dying all over Springfield by loss of habitat, thus contracting a fatal disease. Lisa seeks help from Homer (who at first was unwilling to save the bees until Lisa informs him that the bees make honey and, if they died, there will be no more honey) and Professor Frink who has an uninfected queen bee sting Lisa releasing pheromones which attracts many uninfected bees, which form a bee beard. After trying to keep the bees in the Simpson home, Lisa and Marge find an abandoned greenhouse for the bees to live in. However, the site of the greenhouse is exactly where Mr. Burns plans to construct his new arena.
Lisa attempts to convince the town to save the bee population, but despite her logical protest that they always get into trouble when they ignore her advice, she fails when Burns informs everyone about the amazing features of his arena and threatens to trade the Excitement's recent draft pick and fan favorite, Alaskan native and Eskimo Muk Mu. Lisa becomes depressed that the bee population is slowly dying. Homer and Moe attempt to help save the bees by mating a queen bee from Lisa's hive with Moe's Africanized bees to create a hybrid bee species strong enough to survive anywhere. On the night of the grand opening of Burns' sports arena, Homer takes Lisa to the top of a hill and shows her the hive containing the hybrid bees. When Homer accidentally releases them, the bees attack Burns' arena which resembles a bee hive. In the end, the arena is declared a bee sanctuary, enabling the bees to survive. At the next billionaires' retreat, Mr. Burns reveals how much the bees cost him. After it is discovered that he is four million dollars short of a billion he is kicked out of the retreat and into the millionaires' camp. Much to his horror, these millionaires got rich thanks to their low-class businesses, such as a minor-league hockey team.