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.

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.

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.

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.

Spring, 1918. The Great War is at a crucial stage, the Germans are making one last push into France, and the Allies are struggling to hold them back. Battle lines are shifting, and men, and their machines, are being sent up and down the front to shore up defenses. Major Heathcliff Lennox, and his batman Greggs, are told to report to their new HQ. They set off on a sunlit day to fly the distance, but the enemy is never far away, and disaster strikes. They're sent crashing to the ground behind enemy lines, where life, death, and love await.