This is book makes no attempts at surprising the reader, we know from the opening that someone has died, and the description of the death - "...the bulet smashed into the left side of his skull and tore into his brain, he probably lived for ten to fifteen seconds" is powerful and disturbing. Told as a series of excerpts from interviews after the shooting, this book kept me turning pages to learn more about the school, the dynamics of the people involved and the shooters. We follow the two young men from seventh through tenth grade to the day of the shooting. No where do we get an answer to why they did it, that isn't the point of the book. What we see are the people around them, the friends and enemies, family members, school administration, we see signs, and we see how easily those signs were overlooked.
But that's the message for adults.
or teens, especially young boys, the message is simpler - these two young men, who thought no one cared about them, mattered to more people than they ever realized. Their loss leaves a void in the lives of others. Everyone wants to matter, and I think every reader will see that these young men did matter, not because of what they did at the end of their lives, but because of every moment they lived before that end.