I've recently finished reading Dan Brown's latest epic, assured of massive sales by the phenomenal success of his previous book, The Da Vinci Code. I read TDVC when it first came out, before all of the public furore, and while I didn't think much of the author's writing style I was intrigued by the plot. This was obviously a mixture of fact and fiction and had me guessing as to which was which. It seems it had the author guessing as well, since he took literally a fictional source, but that didn't hurt sales.
The Lost Symbol has an entirely different plot, but it's basically more of the same. It once again features Robert Langdon as the resourceful, code-breaking professor hero. This time the action is more intense and confined, taking place within a small area of Washington DC over a period of just ten hours (which is almost as long as it takes to read the 500 page book). The focus of the plot has shifted away from the Roman Catholic Church and on to Freemasonry. Brown has obviously researched the Masons, their beliefs and rituals, in great depth, but I don't have the knowledge to judge whether his sources are more accurate this time.
The stylistic faults of Brown's other books remain. The writing is humourless and clunky with no subtlety or wit, the characters cartoonish, their relationships sketchy, the plot ludicrous. Finally, the conclusion is weak: the plot builds up a picture of deep secrets and mysterious but devastating consequences if they are revealed, but it all turns out to be a big fuss over nothing. However, the story gripped me sufficiently to keep me turning the pages and I read the last half of the book in one straight session, finishing in the early hours of the morning. That is something which I rarely do, so the story obviously has a strong appeal. What exactly is it?
The arcane "knowledge" which appears to fill the book is certainly an important part of it. There is the strong sense (not necessarily valid, as TDVC demonstrated) of being presented with a huge amount of material which allows the reader to get inside a secret world. He has also packed the book with those esoteric "can that be true?" nuggets, such as that the Christian practice of concluding a prayer with "Amen" actually derives from the worship of Amon, the Egyptian sun god (according to the Wiki entry on "amen", not true). By itself, this would be intriguing but not sufficient. What makes Brown's books so successful is that this material is wrapped up in a driving, relentless narrative which is all-action from start to finish, with more twists and turns than I could keep track of (including a real surprise close to the end).
Basically, to enjoy this book you need to park your critical faculties for the duration and just go with the flow. It will never win any literary prizes but it would be a good distraction on a long flight.