These stories show Holmes' successes, his mistakes, his biographer, and, finally, his nemesis. The ash of his cigar and the length of his stride give the criminal away. Who looks for clues like these? Sherlock Holmes, "the most perfect reasoning and observing machine that the world has seen." Pb. Sonlight resource: https://www.sonlight.com/products/the-adventures-and-the-memoirs-of-sherlock-holmes