England, 1176. Beautiful, tranquil Glastonbury Abbey–according to legend the last resting place of King Arthur –has been burned almost to the ground. The arsonist remains at large, but the fire has uncovered two hidden skeletons, a man and a woman. The skeletons’ height and great age send rumors flying–could they be the bodies of King Arthur and Queen Guinevere?

King Henry II hopes so. Struggling to put down a rebellion in Wales, he wants definitive proof that the bones are Arthur’s. If the Celtic rebels are sure that the Once and Future King will not be returning from the dead to aid them, Henry can stamp out the rebellion for good. He calls on Adelia Aguilar, Mistress of the Art of Death, to examine the bones.

Adelia and her household ride to Glastonbury, where the investigation into the abbey fire will be overseen by Church authorities–in this case, the Bishop of St. Albans, father of Adelia’s daughter. And as if the task of solving the mystery weren’t daunting enough, an unexpected evil waits in the woods near Glastonbury.