Black Powder War picks up right as The Throne of Jade ends. Laurence and Temeraire's mission in China has ended successfully, but it left them with a blood enemy: Lien, the albino Celestial belonging to would-be usurper Yongxing. Now on her own, Lien has flown west towards Europe, where the situation against Bonaparte is still dire. Austria has surrendered completely, and to many it seems as if it's only a matter of time before the Prussians and English fall.
Temeraire is eager to return to England to launch reforms improving the status of dragons in English society, having seen how much more equality and respect they are given in China. It's a goal that Laurence, philosophically, agrees with. But he finds himself forever having to lecture the enthusiastic dragon — who still has a childlike way of not taking the status quo way of doing things seriously — about how slowly it takes people to accept radical social reform. And besides, there's a war to win first.
Before they can leave China, they receive new orders. Three dragon eggs have been purchased from the Turks, and Laurence is to supervise their transport back to England. A fire aboard their ship necessitates their going overland. An adventure in Turkey follows…
You're never quite sure what's coming next in Black Powder War, which ratchets up the suspense beautifully. For most of this novel's length, action is lighter than before, with political intrigue taking up the slack. But as the story moves along, the sense that the whole situation is, in fact, a big black powder keg, with its lit fuse getting ever shorter, keeps tension tight.