When a maid in the upper class Ellison household is strangled, Inspector Pitt is called in to investigate. He finds a world ruled by strict manners and social customs, where the inhabitants of the Ellison's neighborhood appear to be more outraged by the thought of scandal than they are by murder. Inspector Pitt finds a most unlikely ally in Charlotte, the Ellison's spirited daughter. But as the murders continue, Charlotte and Pitt find themselves drawn together by more than the investigation.

The year is 1861. The American Civil War has just begun, and London arms dealer Daniel Alberton is becoming a very wealthy man. His quiet dinner party seems remote indeed from the passions rending America. Yet investigator William Monk and his bride, Hester, sense growing tensions and barely concealed violence.

Hugh of Singleton, fourth son of a minor knight, has been educated as a clerk, usually a prelude to taking holy orders. However, feeling no certain calling despite a lively faith, he turns to the profession of surgeon, training in Paris and then hanging out his sign in Oxford. A local lord asks him to track the killer of a young woman whose bones have been found in the castle cesspit. She is identified as the impetuous missing daughter of a local blacksmith, and her young man, whom she had provoked very publicly, is in due course arrested and sentenced at the Oxford assizes.

His name, they tell him, is William Monk, and he is a London police detective. But the accident that felled him has left him with only half a life; his memory and his entire past have vanished. As he tries to hide the truth, Monk returns to work and is assigned to investigate the brutal murder of a Crimean War hero and man about town. Which makes Monk’s efforts doubly difficult, since he’s forgotten his professional skills along with everything else.

On a sunny afternoon in late June, Cambridge professor Joseph Reavley is summoned from a student cricket match to learn that his parents have died in an automobile crash. Joseph’s brother, Matthew, as officer in the Intelligence Service, reveals that their father had been en route to London to turn over to him a mysterious secret document—allegedly with the power to disgrace England forever and destroy the civilized world. A paper so damning that Joseph and Matthew dared mention it only to their restless younger sister. Now it has vanished.