DAVID GRANN is a longtime staff writer at The New Yorker. He has written about everything from New York City's antiquated water tunnels to the Aryan Brotherhood prison gang, from the hunt for the giant squid to the mysterious death of the world's greatest Sherlock Holmes expert. His stories have appeared in several Best American writing anthologies, and he has written for The New York Times Magazine, The Atlantic, The Washington Post, The Wall Street Journal, and The New Republic. A collection of his stories, The Devil and Sherlock Holmes: Tales of Murder, Madness, and Obsession, will be published in March 2010.Photo credit copyright Matt Richman