Scott Westerfeld already has one amazing world he created, the sci-fi world of his Uglies series, and now he's gone ahead and made a world that's even cooler. Not only is this an excellent alternate history or steampunk book, but it's filled with absolutely stunning illustrations by artist Keith Thompson, though unfortunately the UK version doesn't have them. Boo!
Scott Westerfeld does an excellent, succinct job of summarizing his world in a short interview he did on John Scalzi's blog, Whatever. He states, "In the world of Leviathan, technology has split into two tribes: the Germanic Clankers, who are machine lovers, and the British-led Darwinists, who weave the life-threads of natural creatures into fabricated beasts. (To put it simply, in this world, Origins of Species was an instruction manual.)" In this book, there are tidbits of actual history, strange creatures, amazing technology, strong characters, and a truly original setting.
Alek is the son of the Austrian-Hungarian Archduke Franz Ferdinand. His parents have been assassinated (though in a slightly different manner than actually happened in history.) His son, though he is unable to inherit his father's role because his mother was not of royal enough blood, is on the run for his life along with some bodyguards that I imagine look and sound like Arnold Schwarznegger. Deryn is a young Scottish girl who desperately wants to join the air force. She ends up joining and cross-dressing as a man to do so. I love me some crossdressing in novels, and this works really well.
Eventually, of course, Deryn and Alek end up meeting in a strange turn of events and begin to grow close despite being on opposite sides of a brewing war. They both must re-evaluate their prejudices about the other and have interesting debates about nature vs machines. I also enjoy that they both keep a secret - one is royalty and one is a girl. I won't go into too many plot points because I'm wary of spoilers, but is is definitely an excellent book by one of my favourite young adult authors. I appreciate it when those writing for a younger audience make it fun, but sneak in good life lessons and values. Westerfeld wrote an afterward clearing up was was history and what was fantasy for readers not familiar with WWI. This is one of my favourite reads of the year.