Black Powder War - Naomi Novik

Black Powder War is another book in the series about the dragon Temeraire. Temeraire and his Captain Laurence are on the way back from China when they're commissioned to pickup some dragon eggs the British have purchased from the Ottoman Empire. They decide to go overland instead of by sea, and along the way they encounter deserts, mountains, wild dragons, duplicity in Instanbul, and are caught up in the Napoleonic wars. The continuing dialog between Temeraire and Captain Laurence over the rights and freedoms of dragons is an interesting side thread, and Temeraire's proselytizing among the other dragons they meet is has some interesting consequences.  Their arch nemisis, the white Chinese dragon Lien is tracking them and causing trouble at every turn.  Highly recommended.