Daniel Gerhard Brown (born June 22, 1964) is an American author best known for his thriller novels, including the Robert Langdon novels Angels & Demons (2000), The Da Vinci Code (2003), The Lost Symbol (2009), Inferno (2013) and Origin (2017). His novels are treasure hunts that usually take place over a period of 24 hours. They feature recurring themes of cryptography, art, and conspiracy theories. His books have been translated into 57 languages and, as of 2012, have sold over 200 million copies. Three of them, Angels & Demons, The Da Vinci Code, and Inferno, have been adapted into films.