In the months following Holmes' return from the dead, Watson chronicles a case of a missing child that leads them into the arms of dewy and beautiful Scotland. Spending a week at the Byrne estate and the connected charitable School for Underprivileged Girls, Holmes attempts to uncover what has become Mr. Byrne's daughter - and why he seems so unconcerned with her fate. Holmes and Watson seek to untangle the various motivations of the wealthy sponsors of the school who are there for the week-long annual event, the young girl's aloof father, and the tension simmering between themselves as the trial of Reichenbach and the loss of Mary Watson still looms like a shadow over their renewed partnership. As the truth unfolds, Holmes and Watson realize that the missing young child is the least of their worries as guests and hosts alike begin to be picked off with a cold-blooded efficiency.