Amid civil unrest in the year 1297, human remains are discovered between the tower walls of an English castle in the Scottish lowlands. Kyle Shaw, deputy to the sheriff of Ayrshire, seeks to identify the victim and find out who sealed him up behind the brickwork twenty years earlier. Surely someone connected with the resident family killed him or knows who did. When things take a deadly turn for certain craftsmen who ply their trade in the shire, Kyle has reason to believe the dead man in the tower might not be a victim after all. There may be a link between his sordid past and the fate of those craftsmen.