For the first half of the book, I thought I'd give this one a low rating, truth be told. 
 But somehow, it picked up nicely, especially from the point Joi entered the scene again. She's an awesome young lady to balance the not so quite likable male protagonist. I mean, the dude is not a bad guy but I could not quite care much about him, really. 
 Also, somehow this was not quite I expected: a fun school for young criminals (I do love teen spy schools so, this sounded quite close in spirit) NOT AT ALL. The place is messed up and that may be why i did not really like it at first. 
 And I did not find any interesting supporting characters, the very small development I saw in this matter happened a little bit out of the blue in the last pages... 
 Still, at the end, like I said, the story caught my interest a bit more, hence the 3 stars ;)