Having read the other Dan Brown books, I thought I knew what to expect from this one and unfortunately that was all it delivered. There was nothing novel about this novel. It was just like he'd taken a set template from his other books and filled in the blanks to make it appeal to an American audience. It had the standard wise old man, love interest, crazy fanatic, unsolved codes etc. However for me, this was made worse by the fact that it was about a subject that you would expect to have secret codes and hidden meaning everywhere. It is based around The Masons and unlike his other books which took religion, art, science as their subject matter, this was immersed in a world where codes and mysterious mythology are the whole ethos so the 'revelations' just fell flat. So the Mason's have some strange ceremonies, rituals, beliefs and are full of high ranking Americans, so what? We knew that anyway. Also it's based in Washington DC and all the buildings mentioned were only built in the nineteenth century so it didn't have the feeling of secrets passed down through the annals of time. It was secrets that had only been kept for a few generations. I think this 'history' would have been more interesting to an American readership but frankly, I just didn't care.
The good point of this book is that it is easy to read, not too taxing although the narration is repetitive and Brown's endless listing of religions where xyz is a belief got tedious. There are some twists and turns but whilst you may not see exactly what's coming, you have a good idea. I had to force myself to read the last few chapters though as there was a small chance that the big secret was not the damp squib revealed a few chapters from the end but alas, that was it.
SPOILER ALERT: I was almost glad when Langdon drowned as it did feel like his time should be up. He is a bit of a one trick pony and we've seen enough of him now. It seems there's nowhere new for him to go now. I for one doubt I'll be reading the next book he appears in if/when there is one.