Autumn, 1541. Following the uncovering of a plot against his throne in Yorkshire, King Henry VIII has set out on a spectacular Progress to the North to overawe his rebellious subjects there. Accompanied by a thousand soldiers, the cream of the nobility, and his fifth wife Catherine Howard, the King is to attend an extravagant submission of the local gentry at York.

Already in the city are lawyer Matthew Shardlake and his assistant Jack Barak. As well as assisting with legal work processing petitions to the King, Shardlake has reluctantly undertaken a special mission - to ensure the welfare of an important but dangerous conspirator being returned to London for interrogation.

But the murder of a local glazier involves Shardlake in deeper mysteries, connected not only to the prisoner in York Castle but to the royal family itself. As the Great Progress arrives in the city, Shardlake and Barak stumble upon a cache of secret papers that holds danger for the King's throne, and a chain of events unfolds that will lead Shardlake facing the most terrifying fate of the age.