Columbia Pictures have hired none other than Dan Brown himself to write a second draft of The Lost Symbol screenplay, which is based on his best-selling novel of the same title, after Oscar-nominated screenwriter Steven Knight provided the first.
However officially Dan Brown has never written a screenplay before and Sony are clearly interested in seeing how he’ll adapt his own material.

Brian Grazer and John Calley are set to serve as producers for The Lost Symbol.
But Ron Howard, who directed two previous films also based on Brown's novels, The Da Vinci Code and Angels & Demons, has not committed to return for this third movie. Tom Hanks has not signed up either to reprise his role as Robert Langdon, even though he had said he would be ready to if the novel was made into a movie.
With all these uncertainties, we don't know when the movie will start production.