The writing was of a good quality most of the time (with the exception of some dramatic dialogue that had me rolling my eyes) and it was a very quick read. 
 I did tear up near the end of this book, with two deaths really getting to me because I liked their characters, but I won't spoil it. 
 However, the flashing back to the past did begin to irk me. For example, a gun will be pointed at one of my favourite characters and he's about to pull the trigger and I'm hanging on the edge of my seat and - "when Autumn was three, she liked to dance", blah blah. I didn't want to know that. I wanted to see if my character will be okay. I found myself skipping those parts sometimes. 
 Furthermore, I did have an issue with Tyler's character. He seemed a little like the stereotypical villain. For example, he grins and laughs while he is killing his classmates, and his history with Sylvia didn't help that. I also felt like he needed more justification than 'you were leaving me behind' and 'no one noticed me'. 
 But, I did read this book in a couple of hours and it did create a lump in my throat. It is also the first book about school shootings that I have read, and I think I will be reading more. It's important for everyone to be aware of this topic.