In The Crystal Cave, readers follow the story of the wizard Merlin from the time he is a young boy until the time just before his legendary protege, King Arthur, is born. This classic fantasy novel provides an in-depth exploration of Merlin's formative years, detailing his early mastery of his magic, which manifests itself in clairvoyant visions, and his alliance with High King Ambrosius. The first in a quintet of books exploring these ancient legends, The Crystal Cave begins Mary Stewart's imaginative retelling of the King Arthur legends.
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Their book summaries aren't as good as other providers, but PinkMonkey often has interesting insights that aren't mentioned elsewhere on the Internet. For example, they go over literary elements (like setting, conflict, and mood), compare and contrast, and symbolism/motifs. It's a good site if you want to find a unique fact or angle that other students don't know about.
Includes the standard sections found in most book notes, including a book synopsis, chapter by chapter analysis, author biography, character list, essay topics, book report ideas, and study questions. This website is less comprehensive than other book notes sites, but could be useful if you're looking for a quick review.