Deadzone (Horizon, Book 2)

The survivors have made it out of the jungle, but they may be sorry they ever left when they stumble upon a whole new ecosystem, populated with entirely new threats. And the greatest threat of all may come from within. Because one of the kids is changing... The seven-book series begun by #1 New York Times bestseller Scott Westerfeld only gets bigger and bolder under the frenzied imagination of bestselling, cricially acclaimed author Jennifer A. Nielsen!