Everything you need to understand or teach The Crystal Cave by Mary Stewart.
The Crystal Cave is a story of the life of Merlin before he became associated with King Arthur. The book begins with a Prologue, where Merlin describes being an old man reminiscing on the past. He says that some memories are clearer than others are.
He then describes a couple having a secret rendezvous at a cave. We do not know at the time that they happen to be his parents...
The Crystal Cave Lesson Plans contain 98 pages of teaching material, including: