Summer, 1546.
King Henry VIII is slowly, painfully dying. His Protestant and Catholic councillors are engaged in a final and decisive power struggle; whoever wins will control the government of Henry's successor, eight-year-old Prince Edward. As heretics are hunted across London, and the radical Protestant Anne Askew is burned at the stake, the Catholic party focus their attack on Henry's sixth wife, Matthew Shardlake's old mentor, Queen Catherine Parr.
Shardlake, still haunted by events aboard the warship Mary Rose the year before, is working on the Cotterstoke Will case, a savage dispute between rival siblings. Then, unexpectedly, he is summoned to Whitehall Palace and asked for help by his old patron, the now beleaguered and desperate Queen.
For Catherine Parr has a secret. She has written a confessional book, Lamentation of a Sinner, so radically Protestant that if it came to the King's attention it could bring both her and her sympathizers crashing down. But, although the book was kept secret and hidden inside a locked chest in the Queen's private chamber, it has - inexplicably - vanished. Only one page has been found, clutched in the hand of a murdered London printer.