South-West England 1812. England is at war with America & when two hundred & fifty American prisoners-of-war arrive at Dartmoor prison it is already overcrowded with French prisoners. Among the newcomers is Lieutenant Pilgrim Penn an American merchant seaman who soon falls in love with a local girl at a market held inside the prison walls. The inmates fight amongst themselves despite their common enemy & the Americans are a particularly troublesome group. When the governors daughter becomes romantically involved with one of them he orders his soldiers to open fire during a minor disturbance even though the war has ended & personal revenge is suspected as his true motivation.