Douglas Preston is a renowned author of both fiction and non-fiction, including The Codex, Relic and The Book of the Dead (co-written with Lincoln Child), which topped the New York Times bestseller list for six weeks. He has written articles for The New Yorker, Reader's Digest, National Geographic, Harper's, Smithsonian and Atlantic. He also worked for the American Museum of Natural History as managing editor of Curator magazine.
Mario Spezi is an Italian journalist writing for La Nazione, who has been investigating the Monster of Florence case since the first murders in 1974.