Hint: Book Of Secrets:
Normally, you need to complete the game to unlock the "Book of Secrets". However, you can get into it much earlier than that. In Chapter 4, after getting out of the inn, go to Abnaxus's house on the City Green. Just in front of the staircase is a flower bed. Use the organic plastic (from the Border House, second floor) in the flower bed. The Book of Secrets is now open nine chapters early.