Early in the novel, Perdita suspects infidelity by her husband, Raymond, which leads to a falling out. Additionally, while the world is thrown into turmoil, some characters vie for political control and dominance, as with Raymond’s military conquests in Turkey and Greece. This shows that, even in the darkest times, human nature will still try to take advantage of the situation. On the other hand, Adrian maintains a good heart and spirit in spite of outright enemies and political and social upheaval. Shelley uses the novel to explore the extent to which human nature can be pushed—whether for good or for ill.

As the novel progresses, the world is gradually plunged into terror by the events of the wars and the raging plague. However, later in the book, these threats to human well-being increase still further with the rumor of a black sun and the ominous events it portends. The world is already in disarray, but this new level of fear causes chaos in the streets and begins to tear apart whatever vestiges of society remained. The other terrors were normalized fairly quickly, but when a new portent comes, fear is renewed, and the threat again seems imminent.

Death is explored immediately in the book when Lionel’s father perishes. Throughout the rest of the work, people try to cope with the deaths of friends and family, and come to terms with the potential extinction of humanity. This is the most terrifying thing in the story—the idea that life as we know it may cease to exist—and presents an existential crisis that is far beyond what humans are used to experiencing.