The cathedral town of Litchester is more used to carols by candlelight during the festive period than flames and intrigue, but the proposed sale of its 1225 copy of the Magna Carta in order to raise funds turns out to have far-reaching consequences.

Merchant banker Mark Treasure has been invited down to arbitrate the vicious disagreement between members of the cathedral chapter regarding the sale and finds himself dealing with more than he bargained for when the Dean's verger is discovered murdered, his body left to burn, along with the ecclesiastical library.

As his investigation progresses and the evidence points to mayhem and skulduggery, he discovers that Litchester is a town full of sins and secrets rather than peace on earth.