Content Warning: This source material contains sexual assault and the threat of sexual assault on minors, as well as alcohol addiction and extreme instances of body horror. It also depicts societal anti-gay bias and antisemitism.

Flies symbolize death and destruction. In the context of the plague-era setting of the novel, flies signify the presence of death and rotting corpses. However, flies also indicate the presence of evil, supernatural forces, which are here associated with death. For example, flies often appear before the possession of a human by a demon. Pope Clement remembers that before he died, he heard the buzzing of flies in his room. In particular, flies are associated with Baal-Zebuth, a high-ranking demon in Lucifer’s army often given the title the “lord of the flies.” This connects the symbolism of flies to the manipulation of humanity’s leaders, as these are the people the demons target for possession. Baal-Zebuth’s true form as a demon with a fly’s head reveals that he is the cause of the Black Death and that his death will free humanity from the plague.