Both books are sequels to His Majesty's Dragon. I went out to B&N yesterday afternoon and picked them up. I liked the Throne of Jade more because of the completely different way dragons are used there and finding out more about Temeraire. The Black Powder War was ok but not as much fun. Of course it could have been because it was 5am when I finished it. ;-) The sample for the next book that they tossed in there was interesting. I have to wonder if Temeraire will be able to get the changes he wants because of issues in book 4?