When detectives explored the Chicago hotel owned by insurance fraudster H.H. Holmes in 1894, they found a nightmarish warren of blind passageways, trapdoors, hidden chutes, and asphyxiation chambers in which Holmes had killed dozens or perhaps even hundreds of victims. In this week's episode of the Futility Closet podcast we'll follow the career of America's first documented serial killer, who headlines called "a fiend in human shape." We'll also gape at some fireworks explosions and puzzle over an intransigent insurance company. Intro: In 1908 a Strand reader discovered an old London horse omnibus on the outskirts of Calgary. If Henry Jenkins truly lived to 169, then as an English subject he'd have changed religions eight times. Sources for our feature on H.H. Holmes: Erik Larson, The Devil in the White City, 2004. John Borowski, The Strange Case of Dr. H.H. Holmes, 2005. Harold Schechter, Depraved: The Definitive True Story of H.H. Holmes, 1994. Alan Glenn, "A Double Dose of the Macabre," Michigan Today, Oct. 22, 2013. John Bartlow Martin, "The Master of the Murder Castle," Harper's, December 1943. Corey Dahl, "H.H. Holmes: The Original Client From Hell," Life Insurance Selling, October 2013. "Claims an Alibi: Holmes Says the Murders Were Committed by a Friend," New York Times, July 17, 1895. "Holmes in Great Demand: Will Be Tried Where the Best Case Can Be Made," New York Times, July 24, 1895. "Accused of Ten Murders: The List of Holmes's Supposed Victims Grows Daily," New York Times, July 26, 1895. "The Holmes Case," New York Times, July 28, 1895. "Expect to Hang Holmes: Chicago Police Authorities Say They Can Prove Murder," New York Times, July 30, 1895. "Chicago and Holmes," New York Times, July 31, 1895. "No Case Against Holmes: Chicago Police Baffled in the Attempt to Prove Murder," New York Times, Aug. 2, 1895. "Did Holmes Kill Pitzel: The Theory of Murder Gaining Ground Steadily," New York Times, Nov. 20, 1894. "Holmes Fears Hatch: Denies All the Charges of Murder Thus Far Made Against Him," New York Times, Aug. 2, 1895. "Quinlan's Testimony Against Holmes: They Think He Committed Most of the Murders in the Castle," New York Times, Aug. 4, 1895. "Modern Bluebeard: H.H. Holmes' Castles Reveals His True Character," Chicago Tribune, Aug. 18, 1895. "The Case Opened: A Strong Plea, by the Prisoner for a Postponement," New York Times, Oct. 29, 1895. "Holmes and His Crimes: Charged with Arson, Bigamy, and Numerous Murders," New York Times, Oct. 29, 1895. "Holmes Grows Nervous: Unable to Face the Portrait of One of His Supposed Victims," New York Times, Oct. 30, 1895. "Holmes Is Found Guilty: The Jury Reaches Its Verdict on the First Ballot," New York Times, Nov. 3, 1895. "Holmes Sentenced to Die: The Murderer of Benjamin F. Pietzel to Be Hanged," New York Times, Dec. 1, 1895. "The Law's Delays," New York Times, Feb. 4, 1896. "Holmes' Victims," Aurora [Ill.] Daily Express, April 13, 1896. "Holmes Cool to the End," New York Times, May 8, 1896. Rebecca Kerns, Tiffany Lewis, and Caitlin McClure of Radford University's Department of Psychology have compiled an extensive profile of Holmes and his crimes (PDF). Listener mail: The Seest disaster: https://www.youtube.com/watch?v=l4iNOguCNFQ Wikipedia, "Seest Fireworks Disaster" (accessed March 3, 2017). "Dutch Fireworks Disaster," BBC News, May 14, 2000. Wikipedia, "Enschede Fireworks Disaster" (accessed March 3, 2017). "Vuurwerkramp," Visit Enschede (accessed March 3, 2017). Beverly Jenkins, "10 Worst Fireworks Disasters Ever," Oddee, July 4, 2013. Jessie Guy-Ryan, "Inside the World's Deadliest Fireworks Accident," Atlas Obscura, July 4, 2016. Wikipedia, "Puttingal Temple Fire" (accessed March 3, 2017). Rajiv G, "Kollam Temple Fire: Death Toll Reaches 111, 40 Badly Wounded," Times of India, April 12, 2016. This week's lateral thinking puzzle was contributed by listener Daniel Sterman, who sent this corroborating link (warning -- this spoils the puzzle). You can listen usi