"A Generation" is set in Wola, a working-class section of Warsaw, in 1942 and tells the stories of two young men at odds with the German occupation of Poland. The young protagonist, Stach (Tadeusz Łomnicki), is living in squalor on the outskirts of the city and carrying out wayward acts of theft and rebellion. After a friend is killed attempting to heist coal from a German supply train, he finds work as an apprentice at a furniture workshop, where he becomes involved in an underground communist resistance cell. He is guided first by a friendly journeyman there, who in turn introduces Stach to the beautiful Dorota (Urszula Modrzyńska). An outsider, Jasio Krone (Tadeusz Janczar), the temperamental son of an elderly veteran, is initially reluctant to join the struggle but finally commits himself, running relief operations in the Jewish ghetto during the uprising there.