This book is quite different to previous Discworld books, especially the early ones. This is a book with subtle amusing moments for the reader to reflect upon as opposed to very obvious, laugh out loud humour. It is almost as if Discworld has matured. Lots of the favourite characters are back in this book - Vetinari, Moist Von Lipwig, Blackboard Monitor Vimes, other members of The Watch. There is plenty of action from Goblins and Dwarfs and even the Golems play an active role. This book tells of the coming of steam to Ankh Morpork. There is a subtle reference back to Reaper Man which I nearly missed and has made me want to pick up that particular book again and refresh my memory. As has been the case over the centuries, there are people who welcome the new innovation and those who believe that we should remain set in the ways of previous generations. This is the underlying theme of the book with the story on top of this. There is lots of action in this book including a thrilling fight on top of a moving train - complete with the oncoming tunnel! There is intrigue, spying and a coup to keep the plot moving on. This book wasn't such a quick read as most of his previous Discworld books. I didn't get carried along on a wave of fantasy, action and humour. This book needs to be read more slowly with thought given to the plot and humour. I was slightly disappointed when I started this book as it wasn't in quite the same vein as previous books but I soon adapted to the change in style and enjoyed this book for what it was rather than what I expected it to be. So, start this book with an open mind as opposed to having a preconceived idea as to what a Discworld book should be. Then just settle back and enjoy.