Black Book

Basically unmissable, at least on the lowest difficulty. Use your book of stories and encyclopedia entries to find the answers to questions. If you need help, you can request a hint. Otherwise, just reload the autosave at the location to try again. Most times you are told the answer anyway. I unlocked this while answering the riddles at the Spinner's in chapter one. I only missed one, I answered a river but the answer was a shadow.