Pimlico dozes during the worst heat wave for years, until London's last unexploded bomb from World War II goes off with a deafening roar, flinging the people headlong into a fantastic adventure. Arthur Pemberton and his daughter Shirley, investigating the crater made by the bomb, find treasure and an old document decreeing that Pimlico can be recognized in perpetuity as Burgundian soil. The residents, quick to see the opportunities, put themselves on the export list of English firms.