A young woman faces the social and political upheaval of 17th-century England when her father is imprisoned for his outspoken beliefs. Margaret Pargeter must navigate the complexities of life in London during the Great Plague and the Great Fire, all while attempting to secure her father's release from Newgate Prison. She relies on her resilience and the support of a small circle of allies to survive the harsh realities of a city under siege by disease and fire. The narrative follows her perspective as she balances personal loyalty against the dangerous political climate of the Restoration era. The story maintains a focus on the physical dangers of the period, emphasizing the scarcity of resources and the constant threat of public unrest.

Readers frequently highlight the meticulous historical research that grounds the narrative in a tangible, often grim reality. Discussion often centers on the protagonist's development as she transitions from a sheltered life to one defined by survival and moral conviction. Critics note the effectiveness of the atmospheric writing, which captures the claustrophobia of a city trapped by both pestilence and flames. The balance between personal stakes and broader historical events is often cited as a strength of the work. Many readers appreciate the authentic portrayal of the period's social tensions without relying on overly dramatic tropes.