Empire of Ivory by Naomi Novik

The latest book in the Temeraire series continues to impress. Laurence and Temeraire return from their long trip to China (with the detour to Istanbul) only to discover that a consumption-like illness has put almost all of Britain's dragons out of service. They hasten to Africa to search for the cure (apparently Temeraire had contracted it on the trip to China but was cured in Africa), and in so doing, discover a civilization that's breeding dragons and elephants--which attacks the British settlement at Cape Town because of the slave trade. When Temeraire and Laurence discover that back home, the British government has been acting unethically in its pursuit of the war, they're left with an ethical decision of their own to make. The book was excellent, and I'm really enjoying the way this series plays out questions of duty, morality, and friendship. As a fair warning to all readers, this book ends on a cliffhanger. If you read it, you'll probably need to keep reading the series. Still, if the series keeps getting better, that's not a problem.