The concluding volume of the Temeraire series starts where the previous novel ended, with the Russians and their allies in pursuit of Napoleon as he and his armies withdraw back to the safety of France. While certainly weakened, Napoleon is not done, and still has the ability to wreak havoc, especially by using dragons and politics against his enemies.
The whole series has demonstrated the vast differences in the status of dragons in countries, and focused on the inequality of their status in Europe compared to other regions such as Asia and South America. As a result, appealing to dragons and their rights is a rather smart ploy, so instead of simply fighting battles, Temeraire has to play politics, and get both the allies and the dragons to agree to an alternative.
In addition to the bigger story, there are also some side adventures, especially when Temeraire and Iszierka discover that their egg is no longer safely in China and has instead been stolen and transported to France (given Temeraire and Iszierka’s personalities, their hatchling is naturally something else). In this novel, Temeraire truly shows his growth, both in how he handles dragons, and the sacrifices he shows himself willing to make to help others. While the conclusion wasn’t my favorite novel of the series, it was among the better ones, and served as a fitting conclusion. I wouldn’t have minded seeing a bit more of some of the characters from earlier novels, but was happy to see the ones that did show up received fitting endings after previous struggles.