claim: Dan Brown wrote his first novel in 2006.
evidence: Angels & Demons is a 2000 bestselling mystery-thriller novel written by American author Dan Brown and published by Pocket Books and then by Corgi Books .. Dan Brown. Dan Brown. bestselling. Bestseller. mystery. Mystery ( fiction ). thriller. Thriller ( genre ). Pocket Books. Pocket Books. Corgi Books. Transworld Publishers. The novel introduces the character Robert Langdon , who is also the protagonist of Brown 's subsequent novels - The Da Vinci Code , The Lost Symbol , Inferno , and Origin .. Robert Langdon. Robert Langdon. The Da Vinci Code. The Da Vinci Code ( film ). protagonist. protagonist. The Lost Symbol. The Lost Symbol. Inferno. Inferno ( Brown novel ). Origin. Origin ( novel ). Angels & Demons shares many stylistic literary elements with its sequel , such as conspiracies of secret societies , a single-day time frame , and the Catholic Church .. conspiracies. Conspiracy ( political ). Ancient history , architecture , and symbolism are also heavily referenced throughout the book .. Ancient history. Ancient history. A film adaptation was released on May 15 , 2009 .. film adaptation. Angels & Demons ( film ). The Da Vinci Code film had been released in 2006 .. The Da Vinci Code. The Da Vinci Code ( film )