London, 1899. A shocking murder is discovered at the heart of the Tower of London. The dead body of a Yeoman Warder is found inside a suit of armour belonging to Henry VIII, having been run through with a sword, and when details of this outrage are reported to the Prince of Wales, he fears this may be an expression of Republican unrest striking at the very home of the Crown Jewels. In the hopes of hampering the spread of news about the crime, the Prince reluctantly calls upon the services of Daniel Wilson and Abigail Fenton, the museum detectives, to investigate further.

As their inquiries proceed, Wilson and Fenton learn about the long and bloody history of the Tower of London, but dark deeds are not confined to the Tower's shadowy past. More bones will see the light of day and the twists and turns of a dastardly plot will unravel before the museum detectives' case is closed.