What is the theme of Maximum Ride 2?

The Maximum Ride series is about this girl named Max (short for Maximum--she named herself) and her flock. Yes, her flock. Md scientists kiddnapped this group of 6 when they were young and now they're 2% bird and 98% human. meaning they have wings. If your wondering, the whole flock is ... Max(14), Fang(14), Iggy(14), Gazzy(10-11), Nudge(11), Angel(about 6) Girls are Nudge, Max, and Angel. Guys are Fang, Iggy, And Gazzy. Max is the leader, and none of them are related except for Gazzy and Angel who are the only ones who are brother and sister. Ther, now you know.