The mephit leans over to you and whispers mysteriously, "The treasure is here, inside the library! But to open

The mephit leans over to you and whispers mysteriously, "The treasure is here, inside the library! But to open the way, you'll need to put the right books into the right bookcases. I'll tell you which ones! There are six books and three bookcases: Wrath, Fear, Sorrow. No one likes to read Sorrow, Wrath and Fear, of course. That's why they hid the treasure behind them. When you find all the books, put the good ones on the top shelves, and the bad ones on the lower shelves. Just like that! And you'll get a treasure! See? I'm so useful — I know so much!"