Ralph Delchard, a soldier who fought at the Battle of Hastings, and Gervase Bret, a talented lawyer, have been commissioned by William the Conqueror to look into irregularities brought to light during the compilation of the Domesday Book. A man’s body is found mutilated in Savernake Forest and the residents of Bedwyn sleep uneasy at night, fearing a monster stalking the town. When Ralph Delchard and Gervase Bret arrive, they discover that the locals are harbouring dark secrets and that the real killer may be a little closer to home....

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.

Salisbury, 1226. A young pregnant woman is found tangled in reeds in the river Avon, her identity a mystery. Grieving widow Ela Longespée is determined to succeed her husband as sheriff of Salisbury, and quickly takes charge of the investigation. She soon finds herself in the thick of a neighborhood scandal and a struggle to maintain her authority. With multiple suspects, can she identify the true killer? 

1603. Former ship's surgeon Gabriel Taverner is attempting to re-establish himself as a physician in rural Devon but it's not easy to gain the locals' trust and a series of disturbing incidents convinces him that at least one person does not welcome his presence. Called out to examine a partially decomposed body found beside the river, Gabriel discovers he has a personal connection to the dead man.

September 1907. George Dillman sets sail from Liverpool to New York on the Lusitania's maiden voyage. Posing as a passenger, Dillman is in fact an undercover detective hired by the Cunard Line to keep an eye out for petty crimes. But after some uneventful days aboard, the ship’s blueprints are stolen and then a body is found. As Dillman works to get to the bottom of the crimes, he makes an unusual friend, first-class passenger Genevieve Masefield, and the two uncover secrets aboard the ship that prove explosive.