Not sure if I'll be continuing on with this series...Too much teen angst drama - I might officially be out of the young adult fiction genre. I'm repeatedly finding them too juvenile for myself (currently 25 years old). 
 The crew has escaped the tunnels (subway tunnels) and NYC (can't remember what they called it last book) only to make it to Salvation. Except Salvation isn't what it sounds like and has a whole mess of it's own to handle. This second book in the series is about Deuce's adaptability in the world above and learning to live with actual adults (since they didn't live past a certain age down below). The world of Salvation still sees Deuce as a child (she's 15-16 this book) though she's seen a lot more than any of them ever have within their confined walls. When she sees a chance to prove herself on the summer patrol that she's worth more than sewing dresses she takes it. Freaks are on patrol though and a war is coming (probably in the next book).