This story was very interesting and I like the writing style so much, though I expected a little bit more from this book. 
 What really bothers me about aliens is that (view spoiler)[the reasons of their actions seemed strange to me. I don't completely understand them. Why would they make this camp and train children? Why did they watch people for so many years? They are so advanced, they have very powerful weapons. Why didn't they just kill everyone? Or are they playing with people? Maybe I will discover more about it in the next book. (hide spoiler)] 
 This book was more like 3.5 stars, but I'm giving it 4:)