The story portrayed in the book is a slightly fictionalized account of real lives of Gray Rank members (known by their noms-de-guerre of "Rudy", "Zośka", and "Alek"), with the final act centred on the Operation Arsenal. The book tells the story of a group of Polish boy-scouts taking part in resistance movements in nazi-occupied Warsaw. A major part of the book revolves around trying to rescue "Rudy" from Gestapo captivity. Despite the success of the operation, "Rudy" dies shortly afterwards from grave injuries caused by torture during German interrogations, with "Zośka" by his side. "Alek" dies at the same time from wounds sustained during the rescue, while "Zośka" is killed a few months later in another operation.