Holmes: "What's the matter? You're not looking quite yourself. This Brixton Road affair has upset you."

Watson: "To tell the truth, it has," I said. "I ought to be more case-hardened after my Afghan experiences. I saw my own comrades hacked to pieces in Maiwand without losing my nerve."

Holmes: "I can understand. There is a mystery about this which stimulates the imagination; where there is no imagination there is no horror ."

• From Conan Doyle's "a study in scarlet" (bold added by me for emphasis)