Sherlock Holmes fans span the range from casual to obsessive. They included Abdulhamid II, the last ruler of the Ottoman Empire to hold absolute power. A description of the sultan having Holmes stories read to him at bedtime set journalist Andrew Finkel off on the flight of fancy that became his first novel. We spoke about The Adventure of the Second Wife, the Sherlock Holmes craze, the dying days of the Ottoman Empire, and the nature of obsession.