A wounded army doctor home from Afghanistan takes cheap lodgings with a chemistry-obsessed stranger who can read a man's history off his cuffs and boots — and who is soon called to an empty Brixton house where a corpse lies unmarked beside the word RACHE scrawled in blood. Halfway through, the story abandons London altogether for the Utah desert and a long, hard tale of Mormon zealotry, a forced marriage, and a slow revenge, before snapping back to the sitting room for the solution. This is the case where Sherlock Holmes and Dr. Watson first shake hands — the detective the world would never let Doyle retire arriving, at his very first outing, almost fully formed.