Rex Harpham's debut novel takes Holmes and Watson to the Highlands of Scotland where in the words of the great detective "it is my belief, Watson, founded upon my experience, that the lowest and vilest alleys in London do not present a more dreadful record of sin than does the smiling and beautiful countryside" (The Adventure of the Copper Beeches). Inverdaigh House and estate, home to Sir Hugh McFarlane, with its extensive woods, loch and thunderous waterfall, known locally as the Hissing Shaft, present an idyllic setting, but one where repeated attempts are made upon McFarlane's life. Finding the local police of limited assistance, Holmes and Watson are soon faced by a ruthless adversary determined to bring death upon their client. They will need all their courage and skills to avoid traps set for them as they become the prime target in a tense game of cat and mouse, which will culminate in a boat chase across the loch.