We had to take a break from reading for a few days because our regular library did not have this book on the shelf. My children were so sad on Thursday when we came home with just books 4 and 5. They paged through them and read some picture captions and such, but I decided to wait until we had read the third to keep going. On Monday we went to a different local library to borrow their copy which was available. In book three we meet Aunt Lucinda or Aunt Lucy who owns the house the children are staying and is currently living in an institution because she is believed to no longer be sane. Lucy knows about the fairies and has been treated unkindly by them because they want her to give them the field guide. Even though Jared found it in the attic of the house she never had in all of her years living there alone. Aunt Lucy is very worried for the children and shares some history they were unaware of, her father who wrote the guide disappeared one day years ago when she was a child. He went out for a walk and never came back. This changes the children's perception of what kind of man Arthur was during his time.
More fairy creatures appear in this installment as well such as a phooka, a unicorn and wood elves. More beings are wanting to find the book to either destroy it or use it.