I knew this would be a book on King Arthur and the Grail, what I didn't expect was a meandering tale of his mother Ygrane, his sister MorgueLeFey, Merlin, and devils named Lucifer, Loki, and the fairies ( called here as Daoine Sid ). I am wondering about the mention of a dragon slumbering at Earth 's core and a world tree. This story gets very loose in its weave, and uses a lot of ancient folklore magic and beings.