What does the lord of the flies tell Simon in Lord of the Flies?

The Lord of the Flies, or the pig's head on a stick, tells
Simon what he has already begun to suspect as the most insightful character in the
novel.  As Simon has tried to figure out exactly what the beast is, suggesting an
investigation of the thing that the twins saw and watching the different groups of boys
change as time on the island goes on, he has begin to have an insight that the rest of
the boys lack.

And in his vision of the Lord of the Flies,
it tells him that the reason it is all going wrong is that the evil, the beast is a part
of them, it is inside of them.  Unfortunately the vision does the boys no good as they
accidentally kill Simon in the excitement of him running out of the jungle to tell them
what he's learned.