A bone of contention

Cambridge, 1392. Matthew Bartholomew, physician to Michaelhouse College, is called to examine some mysterious bones found in the King's Ditch. The next day he is called to the Ditch again: a student has been found dead there. Meanwhile, it seems Dominica, former lover of the dead student, has disappeared. Are these events connected? Then a skeletal hand is found in the Ditch, hailed by townsfolk as the final remains of local martyr Simon d'Ambrey, and hence a holy relic. When Bartholomew finds that the hand is wearing a ring apparently identical to a pair worn by Dominica and her ex-lover, he knows that his investigative skills are called for.