Eric is overweight and on the swim team, so he is called Moby by many people. Sarah has lived since she was a young child with horrible burns over her body, and so she makes people address her by her full name to keep them from making jokes because Byrnes is pronounced like "burns".
There is some heavy stuff in here. I'm talking abuse and neglect of children, suicide, strong violence in some parts, and that's only a part of it. More than once I had to put the book down to give myself a break before coming back to it.
It does a good job of presenting these things to a teenage audience, even if the story is over a decade old and it doesn't involve certain technological advances like the cell phone.
Anyway, I enjoyed it. It causes a lot of thinking and some strong emotions. You should check it out.