Writing 15 years after the end of World War II, the narrator Pilenz tells the story of his high school days and the following years, especially involving his friend Mahlke. Set in Danzig after it was annexed by Nazi Germany, the novel uses the characters to explore the tensions that the people experienced in their complex relationship to the war.

Pilenzs is writing in part to expiate his guilt over his treatment of Mahlke. As a youth, he taunted him, mocking his friend's insecurities to bolster his own popularity. Years after they leave school, his insincere and limited efforts to help his needy friend almost certainly contribute to his death. As an adult, Pilenz (who is Catholic) works as a secretary in church-related social services.

Mahlke, an awkward and naive boy, goes to great lengths to cover up his perceived inadequacies but only succeeds in drawing attention to them. Pilentz points especially to his huge Adam's apple. Mahlke's misguided worship for the Nazis, encouraged by their school headmaster, precipitates a series of disastrous events. Obsessed with the symbolic surface of Germanic patriotic heroism, the Iron Cross, Mahlke first steals one then joins the war effort so he can earn his own. Continued conflict with the headmaster leads to Mahlke's final undoing. Unable to survive without Pilenz's help, he disappears and—the reader concludes—dies alone.

Headmaster Klose at the Catholic school the boys attend is harsh and even cruel. He promotes the ideology of militaristic patriotism by bringing decorated soldiers to speak at the school, stimulating Mahlke's envy. A Nazi, but a civilian, Klose represents the collaborators who contributed to advancing Germany's interests. His expulsion of the boy sets in motion Mahlke's disastrous course of action.

Father Gusewski, the priest at the boys' church, is kindly but ineffectual. His spiritual guidance may offer consolation but, though well intentioned, does not help Mahlke.

Tulla Pokriefke is a girl who is friends with the boys and kind to Mahkle. She boldly takes part in their dangerous games on a sunken boat. Winter and Hotten are two other boys in the boy's pack of friends.