An illiterarte single mother, Agnieszka Kowalska is a Socialist "heroine of labor" for working long hours as a shipyard welder. This is until her superiors deny compensation to the widows of 21 workers killed in an industrial disaster. Risking her job, her life, and the love of her son to defy the bureacracy, Agnieszka inspires the largest labor strike in world history. By doing what she felt was right, Agnieszka becomes a national hero.