The symbolism of Big Ben
Big Ben is symbolic of the sovereignty of British soil. In other words, if Big Ben sounded each day, then the soil of the United Kingdom was free; if it did not ring, then the Nazis had invaded, and the soil and people of the United Kingdom was not free.
The symbolism of the BBC
The BBC is a powerful symbol of the freedom of the press and the desire (and ability) of the British people to stay knowledgeable about World War II and the situation they have found themselves in.
The motif of death
Death is a common motif in the novel. Throughout the novel, people—most of whom are innocent—die. That includes Sam, the main character of the novel who dies at the hands of Nazi German umbrella bomb. Naturally, war brings death; the novel warns that death is a natural consequence of war.
The motif of Nazi aggression
Nazi aggression is another important motif in the novel. It was Nazi aggression, after all, that started World War II. It was also Nazi aggression that resulted in the start of the Blitz, a bombing campaign which is at the center of the novel.
