Spring, 1543. King Henry VIII is wooing Lady Catherine Parr, whom he wants for his sixth wife. Archbishop Cranmer and the embattled Protestant faction at court are watching keenly, for Lady Catherine is known to have reformist sympathies.

Matthew Shardlake, meanwhile, is working on the case of a teenage boy who has been placed in the Bedlam insane asylum, before his terrifying religious mania leads to him being burned as a heretic.

When an old friend is horrifically murdered Shardlake vows to bring the killer to justice. His search leads him to Cranmer and Catherine Parr - and to the dark prophecies of the Book of Revelation.

As London's Bishop Bonner prepares a purge of Protestants Shardlake, together with his assistant, Jack Barak, and his friend, Guy Malton, investigate a series of horrific murders which are already bringing frenzied talk of witchcraft and demonic possession - for what else would the Tudor mind make of a serial killer . . .?