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? 

London, September 1666. The Great Fire rages through the city, consuming everything in its path. Even the impregnable cathedral of St. Paul's is engulfed in flames and reduced to ruins. Among the crowds watching its destruction is James Marwood, son of a disgraced printer and reluctant government informer. In the aftermath of the fire, a semi-mummified body is discovered in the ashes of St. Paul's, in a tomb that should have been empty. The man's body has been mutilated, and his thumbs have been tied behind his back.

London, 1654. Oliver Cromwell is at the height of his power and has declared himself Lord Protector. Yet he has many enemies at home and abroad. London is a complex web of spies and merchants, priests and soldiers, exiles and assassins. One of the web's most fearsome spiders is Damian Seeker, agent of the Lord Protector. No one knows where Seeker comes from, who his family is, or even his real name. All that is known of him for certain is that he is utterly loyal to Cromwell and that nothing can be long hidden from him.

Bordeaux, 1367. Having angered the bloodthirsty Don Pedro, King of Castile, Sir Thomas Blackstone is thoroughly sick of his mission for the Prince of Wales, but must remain true to his oath. But this is the Hundred Years' War, and tensions are rising once more. With the Prince of Wales deeply unpopular in his Aquitainian lands, Blackstone, King Edward's Master of War, must return to French soil to help stem the tide of support for the King of France. Meanwhile, Henry, Blackstone's son, faces an incognito ride across France with his own motley band of outlaws and mercenaries.

Present day: When thirty-six-year-old Robyn Willoughby discovers an exquisite yet blood-stained Tudor map in her father’s antique map shop, desperate for a distraction from her problems, she decides to investigate. But as Robyn delves into the mystery, she finds herself caught up in a centuries-old secret—one that will change her life forever.