The Crystal Cave is one of a multitude of fictional works pertaining to the times and life of the legendary King Arthur. It differs from the others however, in that it focuses on the life of the great enchanter Merlin, who although intrinsic to the legend, rarely is considered by authors as a principal character of their stories. Generally, Merlin is presented as a learned sage of whose earlier life little is known. Mary Stewart shows Merlin to be more human, than the reader has encountered him in the other Arthurian tales. She achieves it by creating for him a childhood and parentage. In the popular myth it is believed that Merlin was a devil- begotten child, hence his magical powers. The Crystal Cave shows him a very real person possessed of heightened perceptions and extraordinary intellect, which a medieval audience, whence the original stories of Arthur stem, would very likely have equated with powers beyond an ordinary mortal. The book is an engaging and highly probable tale, beautifully written and entertaining. Mary Stewart cleverly links her story with original legend and her fresh approach makes for excellent reading. Even an adult reader well familiar with the legend will be transported to another world, one he might not have visited since his childhood days.