In the summer of 1358 Matthew Bartholomew finds himself one of a party of Bishop's Commissioners, sent north to investigate the mysterious disappearance of the Abbot of Peterborough. He and his colleagues quickly learn that behind the beautiful façade of the Benedictine monastery there is a vicious struggle for power, and that not everyone would be happy to see the prelate's safe return.
This unrest and discontent seems to have spread throughout the town, and there are bitter rivalries between competing shrines and the financial benefits of the relics they hold. One of these shrines is dedicated to Lawrence de Oxforde, a robber and murderer who was executed for his crimes, but who has been venerated ever since miracles started occurring at his grave. But when Bartholomew and his friend Brother Michael go to investigate, they find murder instead...