Hector Cairns, son and heir to Sir Hugh Cairns becomes 17yrs old and still attending school. His father succumbs to injuries from the assassination attempt in part one. Before his death he endows the care of his son to his brother Thomas, and the estate. Thomas Cairns schemes to have Hector disinherited in order for him and his son to take custodianship of the late Sir Hugh's assets (sixth earl of Lanark).