Black Powder War (Temeraire, #3)

Picking up where book two left off (in China, Macau) Captain Will Laurence and his extraordinary dragon, Temeraire, are ordered to retrieve and escort a precious cargo of valuable dragon eggs from Istanbul to England. They take the Old Silk Road from China to Istanbul, crossing deserts and mountains. En route to England, they help the beleaguered Prussians battle Napoleon.