I've gotten terribly behind on this blog (7 books behind) and I can't really remember the order I read some in or when I finished them, so this is just my best guess.
This is the second book in the Gregor series. Gregor returns to the underland to fulfill yet another prophecy. This book was better than the first one with some additional fun characters through into the mix. The fireflies are both hilarious and infuriating, while the newest rat Twitchtip keeps you guessing. Gregor continues to struggle to interpret the prophecies and understand his new friends all while having to make some of the most difficult decisions of his life. You can't help but love him, his sister Boots or even the various rats, bats and cockroaches that accompany him.