The Scar by China Miéville

I really enjoyed this book, although you never know quite where everyone stands. Bellis Coldwine is fleeing New Crobuzon because she has noticed that the government has been going after the friends and acquaintances of Isaac Dan der Grimnebulin. But before her ship can reach its colonial destination, it's hijacked by the Armada, a mysterious floating city on its way to great things under the leadership of the Lovers. Bellis finds herself caught in webs of betrayals, where no one is trustworthy, as she moves through a fantastic landscape. This book is really well written and full of thrilling ideas.