A man navigates the harrowing social and physical collapse of London during the 1665 Great Plague, documenting the disintegration of order within the city. Through the eyes of the narrator, H.F., the reader observes the implementation of quarantine measures, the panic of the populace, and the grim realities of mass mortality. The narrative functions as a pseudo-historical record, utilizing a first-person perspective to maintain a sense of immediate, ground-level observation. The protagonist must balance his desire for self-preservation with the necessity of witnessing the city's transformation under the weight of the bubonic plague.

Discussion often centers on the effectiveness of the narrator's detached, journalistic tone in conveying the scale of the tragedy. Readers frequently highlight the contrast between the book's clinical, data-driven approach and the visceral, human suffering depicted in the streets. Critics often note that while the work is technically fiction, its commitment to historical accuracy and research makes it a primary reference point for understanding the period. The lack of traditional narrative structure is frequently cited as a stylistic choice that reinforces the chaotic nature of the plague itself. Many readers appreciate the balance between the narrator's personal reflections and the broader social commentary on human behavior during times of crisis.