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.

1715. Jonas Flynt, ex-soldier and reluctant member of the Company of Rogues, a shady intelligence group run by ruthless spymaster Nathaniel Charters, is ordered to recover a missing document. Its contents could prove devastating in the wrong hands. On her deathbed, the late Queen Anne may have promised the nation to her half-brother James, the Old Pretender, rather than the new king, George I. But the will has been lost. It may decide the fate of the nation.

England 1616. Robert Belstrang, ex-magistrate bored with country life, comes to London to investigate the strange disappearance of Thomas Jessop, son of a poor Catholic neighbor. He locates the youth in Bedlam asylum, silent and starving himself. When he tries to free Jessop, he is warned off the case by a politic lawyer, Anstis. Soon after, Belstrang finds himself drugged, robbed and falsely imprisoned. Once released Belstrang persists in his investigation, but he is thwarted at every turn: unseen forces are at work who seemingly want Thomas Jessop to die. 

April 1284. As a newly widowed lady-in-waiting to the very pregnant Queen Eleanor of England, Catrin never expected to return to Wales again. She was definitely unprepared to be confronted with murder when she got there - or to find herself face-to-face with Rhys, the childhood friend she lost 20 years before. Rhys had never intended to return home either, but a lifetime of war has deposited him right back where he started - impoverished and owing service to Catrin's older brother.

Sir Francis Walsingham, spymaster to the Tudor Queen Elizabeth has trained Kit Scarlett since she was a girl. Aware that she is able to infiltrate places that his male agents cannot, he sees her as an invaluable member of his team. When Walsingham discovers that a rebel alliance is planning to overthrow Queen Elizabeth and put Mary, Queen of Scots on the English throne, he summons Kit immediately. Together with loyal Scottish agent Iomhar Blackwood, Kit is tasked with finding out the full details of the treasonous plot.