 In the episode, Del buys a nuclear fallout shelter and, anticipating a nuclear war, the Trotters decide to build it.Del Boy purchases a pile of bricks and discovers several boxes of lead underneath, Rodney discovers (in some old paperwork found with the lead) that the lead is for a do it yourself nuclear fallout shelter.The episode was first screened during the Soviet–Afghan War, and Rodney persuades Del that, with a potential World War III looming, they should build the shelter rather than sell it.