England, 1560 - The mysterious fate of Amy Dudley threatens to ignite a rebellion that could destroy Elizabethan England. A reluctant Sir Samuel Banks, a former royal spy and death doctor, is tasked to discover the truth about Amy Dudley's death. His investigations lead him into the dark underbelly of Elizabethan politics and to the Watchers who threaten not only his country but his life and all he holds dear. Can Sam survive the Watchers and uncover the truth about Amy Dudley before it's  too late?

Edinburgh, 1840 - Doctor Gordon McCraken seeks escape from tragedy and his unravelling mind by attempting to expose what really happened to Lady Amy Dudley, and why. With only fragments from the Sam's 1560 investigation Gordon's journey for answers will take him far from Edinburgh, but he's not the only one searching and some secrets are best left hidden. For hundreds of years the Watchers have waited, now they have a quarry.

Oxford, 2007 – When her great aunt dies, Iris Shaw receives a dangerous bequest; to save Lady Amy Dudley’s condemned soul. Driven by her own dark secrets and continuing Sam and Gordon's investigations, Iris sets out to finally reveal the mystery behind Amy Dudley's death. But the Watchers have never stopped searching and now they know where to strike. Can Iris outwit the age old faction to solve the case and save everything she loves before the Watchers destroy them all?