I think the narrator sounds just a little too much like you in the beginning. Also, the age of the characters doesn't seem to really match up with the way they are thinking (muttering) about things. Somehow the behavior of the boy doesn't feel like an eighth grade boy, as evil and immature as they are. I think it seems just a litle to slow in telling us about the older brother. And I'm not sure you used osmosis right. It feels funny. And I guess you didn't tell us the main character's name on purpose, but it might be a nice thing to know if this ever continued.

I sounded a lot more critical than I meant to. It's an interesting story, and good character development, and a lot of real and well-written emotion. I did like it, a lot. You should continue more of your other non-fic stories.