I loved the fact that we get to explore the wilds in the book and see what life's like outside of the fence. Lena meets some interesting characters, and of course gets herself in a sticky situation. I fell in love with Julian,a boy who plays a bit part in Pandemonium.
The end was a major cliffhanger, even if I saw it coming. I can't wait till Requiem so that I can see what happens. Amazing novel!