What if WWI was steampunk? If England could use DNA to combine animals and create giant warships, or if Austria-Hungary had giant fighting monsters of steel? This is exactly what happens in Scott Westerfeld's book.
Alek's parents have been murdered, and by order of the Pope Alek has been named the heir to his grand-uncle's lands: Austria-Hungary. He is on the run with a loyal group who whisk him away to Switzerland where he can hopefully be safe from the Germans and his grand-uncle's men. Dylan is a girl who wants more than anything to be an airman, even though women aren't allowed to go into service. She dresses as a boy, and soon finds herself to be one of the best of the "newbies" on the Leviathan. Through a twist of fate these two meet, and an adventure unfolds.
An easy read that has delightful illustrations on some of the pages, this book shares an interesting "alternate reality" to the one we exist in today.