Unfortunately I had too many problems with this book as in with its world-building and characters alike to actually enjoy it.
It seems to me this dystopia was a clash of too many ideas, which together created a great mess.
The world is separated into savages and so-called aristocratic society stuck in Victorian era under the protection of steam-powered domes. However in the centuries since the domes creation this society hasn't bothered to monitor changes of the outside world so it comes as a great surprise for them that it's actually now livable. What kind of disaster made the atmosphere dangerous for humans in the first place is not very clear.
The savages have a confusing tribal system, but they have a president (presidents?) and they are not really savages. There comes the line about their genetic modification, specific breed of warriors and special mates for them... Eh, too much.
Clara's willingness to go through abuse of her perpetually drunken mother and a potential abuse from her fiance didn't make sense to me as well. Her people were behind her, most of the aristocracy was behind her. The elimination of the queen who is incapable of ruling properly should have been in the works, maybe not by Clara herself, but by certain groups among the aristocracy. Clara's plot to just escape and hide wasn't going to work anyway.
Oh, well. I know a lot of people loved this book, but sadly it wasn't for me.