It's beyond amazing! The writing is daring, bold, and clever. The book doesn't spare the reader from any stomach-lurching details!
The character development of Cole, a troubled boy who believes the world is after him and is forced to an island for exile after he bashed a boy's skull in, is clever. The way Mikaelson writes makes us understand what he's thinking, not even through just Coles's actions and dialogue. Deep point of view is the only way I can describe it, it's just better to read the book :)
We also see the reasons why Cole acts the way he does through flashbacks, which at the start when he blames others for his actions, is frequent, but as he matures, flashbacks are kept to a minimum.
Although Cole is the main focus, a lot of the characters all play a key and a lot of them do have character development that evolves with Cole, such as Peter the boy who got his head smashed in (which is seen beautifully in the second book,) and Coles mother.