Inferno: A Novel (Robert Langdon)
A prisoner of his formula.
Dan Brown is a prisoner of his formula, finding some odd historical theory and exploding into a novel. Angels & Demons was fun, The Da Vinci Code was inspired, and Inferno is just.....tired. Too much "tour guiding", and forced plot derived from Dante's Inferno.
He should break out of his prison and try something new.