In August, 1494, a young woman's body is found bound and strangled at St Mungo's Cross in Glasgow, Scotland. The victim had been left there alive the previous evening as a punishment for her madness but during the darkness hours had been cruelly killed. Lawyer Gilbert Cunningham, who, as the most educated man locally, is often asked to look into any murders that occur, goes with his assistants to investigate the matter.

After questioning all of the relevant witnesses and other associated locals, it became clear that the body of the corpse was different from the person who had been tied up the previous evening! So where had the mad girl gone and who was the person who was murdered?

Gil Cunningham and his assistants ride all over Glasgow and the surrounding area, questioning people and trying to establish the facts in this fast moving medieval Scottish mystery until the surprising conclusion.