Oh, today's kids are used to violence alright, so that aspect probably wouldn't even cause an eyelash to bat. But why would they market a book in which incest is a main theme for kids?!
Oh, I have it - the word "children" in the title does it! It just
has to be a children's book!
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'Mercy!' cried Gandalf. 'If the giving of information is to be the cure of your inquisitiveness, I shall spend all the rest of my days in answering you. What more do you want to know?' 'The whole history of Middle-earth..
.'