Young Highland Guardsman Corporal Craig is found shot, his corpse containing bullets from three separate guns. He has been shot by a firing squad, for treason, and when Steed re-enlists in the Army under his old rank of Major, he could very well end up the same way, thanks to a bizarre plot by latter day Jacobites, whose plan is to overthrow the monarchy and crown a descendant of the Stuart dynasty, a descendant who just happens to be Mrs. Gale!
—don @ minifie-1