Ah, metafiction at its best.
The plot is actually very simple. Anyone who knows about fanfiction knows about Mary Sue (http://tvtropes.org/pmwiki/pmwiki.php/Main/MarySue)'s. And if you don't, then read the link and the sort of character I am referring to will become very clear.
So anyway, the heroes of the story, the PPC, go through various fanfic stories, killing as many Mary Sue's as possible, in order to restore the canon plot and return other characters to normality. And hilarity ensues.
The series can be found here: http://www.misssandman.com/PPC/ppc.html