 The story is based on the Battle of Leros, and Leros island's coastal artillery guns – among the largest naval artillery guns used during World War II – that were built and used by the Italians until Italy capitulated in 1943 and subsequently used by the Germans until their defeat.The story concerns the efforts of an Allied commando team to destroy a seemingly impregnable German fortress that threatens Allied naval ships in the Aegean Sea, and prevents over 1,200 isolated British soldiers from being rescued.The story is based on the real events surrounding the Battle of Leros in World War II.