Mr. Bean and the father-and-son compete for the incoming biggest marrow competition. Thanks to the super light lamps, Mr. Bean's marrow grows heavier and heavier until the father and son decide to sabotage it by putting caterpillars in Bean's marrow. The next day at the competition, they swap their marrow with Bean's while he is not looking, but they fail to realise that their caterpillars are inside. Seeing this, Bean convinces the judge that the marrow he is holding is his and ultimately wins the trophy.