Sherlock Holmes and Dorian Gray walk into a bar...

An interesting anecdote found in a NY Review of Books piece on Arthur Conan Doyle:

Secret sharers, deception and disguise, imposture, buried shame and repressed evil, madwomen in the attic, the covert life of London, the concealment of depravity and wonder beneath the dull brick façade of the world—these are familiar motifs of Victorian popular literature. In 1889, J. M. Stoddart, American editor of Lippincott's Magazine, took Oscar Wilde and another writer to lunch, over which he proposed that each man write a long story for his publication. One of his lunch guests that memorable day went off and dreamed up a tale of an uncanny, bohemian, manic-depressive genius who stalks the yellow fog of London, takes cocaine and morphine to ease the torment of living in this "dreary, dismal, unprofitable world," and abates his drug habit by compulsively scheming to peel back the commonplace surface of other people's lives, betraying secret histories of violence and vice. Stoddart published Conan Doyle's second Holmes novel as The Sign of Four. Wilde, for his part, turned in The Picture of Dorian Gray.