Throughout the novel, adults and adolescents clash in increasingly tense scenarios that finally climax with the tragic shooting of the German soldier near the bomb shelter. Chas McGill, the book's central character and the driving force behind the fortress-building, is an intelligent fourteen-year-old who lives in Garmouth. Chas knows how to manipulate his parents: he condescendingly tolerates his mother's apparent ignorance, and he tricks his father into building a tripod for the machine gun.

Chas has only a surface relationship with his parents, and he knows that things run more smoothly at home when he is not there. His questions often annoy his father and mother, who avoid discussing things that they consider embarrassing, such as the drunken widow's home full of sailors. This lack of information frustrates Chas and makes him feel overly protected. Heavily influenced by the war tales told by his...