The accidental detonation of an unexploded World War II bomb in Pimlico, London, England reveals a treasure trove. Residents find documents proving that the region is, in fact, part of Burgundy, France--ergo, it's foreign territory. The British government attempts to regain control by setting up border controls and cutting off services to the area, and the "Burgundians" fight back.
Passport to Pimlico
Residents of a part of London declare independence after they discover an old treaty, which leads to the need for a "Passport to Pimlico".