Leviathan ranks among the best of the new steampunk genre. An alternate history of WW I, Leviathan begins with the assassination of the Austrian Arch Duke Ferdinand and his wife and in many ways provides a good overall background of the intricate alliances that resulted in the Great War. But Westerfeld has taken some of the events of WW I and moved them to his own imaginative world - and what a world! The alliances are still the same - British/French against the Austrians/Germans but what Westerfeld has changed is the technology and weapons used on each side. The Austrians and Germans use Klanker technology - huge machines that can walk on all types of terrain, fly in the sky, shoot weapons of not so mass destruction, all controlled by a single skilled pilot. The British are known as the Darwinists and their weapons are genetically engineered creatures that symbiotically co-exist to create massive living beings that match up with the best of the Klanker artillery. The creativity behind these Darwinist creations is pure genius and reading about them is pure fun. I listened to the audiobook but this is a book that you also want to see in print. Illustrator Keith Thompson's black and white drawings of both the Klanker and Darwinist creations are not to be missed. Highly recommended!