Like all Dan Brown's Robert Langdon books, the action is super-fast paced and action packed.  His works remind me a lot of Alistair McLean or Desmond Bagley books in their formula.As mentioned, I thoroughly enjoyed this book right up until about the  point, where I couldn't put it down for fear of losing the thread of all the different plot lines.  It just got too busy.Great book, but it could have done with 1 or 2 less twists.This is another great book from Brown, but some advice?  When to go to read it, I'd really suggest you clear a day and just go at it.  It deserves your undivided attention.Basic premise - Langdon wakes up in a small Italian Hospital with no knowledge of how he got there and just get's swept along in his struggle to make sense of it all.  SPOILER alert:What he finds is that some madman or group is planning to poison the world population in some misguided save the planet type environmental mission. 

Question: Does its contains a lot of action?
Answer: fast paced and action packed