Douglas Preston worked as a writer and editor for the American Museum of Natural History and taught writing at Princeton Univeristy. He has written for The New Yorker, Natural History, National Geographic, Harper's, Smithsonian, and The Atlantic. The author of several acclaimed nonfiction books, Preston is also the cowriter with Lincold Child of the bestselling series of novels featuring FBI agent Pendergast.
Mario Spezi, a highly decorated journalist, has covered many of the most important criminal cases in Italy, including those invovling terrorism and the Mafia, and has been investigating the Monster of Florence case since its beginning. He has also published both fiction and nonfiction books in Italy and several other countries.