Not sure if this is the right book, it was definitely Edge 33 but had the title of The Hated.
Anyway, a blast from the past, a read of one of the series of books which were a part of my schooldays reading. It's ok, but every chapter seems to end on a pun by Edge, some of which are horribly contrived, which grew a bit wearisome after a while. Probably won't bother with any more as, even second hand, they're a bit pricy.