Westerplatte is a small peninsula at the entry to the Gdańsk Harbour. Before World War II, it functioned as a Polish ammunition depot in the Free City of Danzig. Its crew consisted of one infantry company and a group of civilians, 182 people in total. It was the only Polish guard-post at the mouth of the Vistula River, with as little as five sentries, one field cannon, two anti-armour guns and four mortars. The first shots of World War II were fired there. This film tells the story of Westerplatte's courageous defenders.