Welsh setting in The Grey King and Silver on the Tree is the area around Aberdyfi, the village where Cooper's grandmother was born and where her parents lived. Critical reception John Clute wrote in The Encyclopedia of Fantasy "The overall tale evolves – not without occasional narrative confusion when time paradoxes and puzzles must be confronted – towards a guardedly affirmative climax in which it seems that the various young protagonists plus Bran Davies (King Arthur's son) may succeed in staving off entropy and totalitarianism." Karen Patricia Smith wrote "Susan Cooper has come to be recognized as a major author of books for children and young adults. Her first work for children, Over Sea, Under Stone came as a response to a contest designed to honor the memory of E. Nesbit. Cooper's major contribution to date has been The Dark Is Rising series, which greatly expands the mythical theme suggested in Over Sea, Under Stone and reveals Cooper's extraordinary prowess as an author of fantasy... The shadowy aspect of the conflict and the inability to 'read' clearly the motivations of some of the characters are areas in which Cooper has been criticized. However, I feel that the ambiguity of protagonists and antagonists is a deliberate literary device. Rather than succumbing to artistic flaw, Cooper goes beyond the conventional expectations of her readers by inviting them to glimpse the complex, the unexplainable, and often the threatening aspects of mankind's nature. By offering the thesis that the human psyche may manifest itself in explicit actions or present itself in a mysterious and often frustrating manner, Cooper exceeds the traditional presentations of good versus evil often found in fantasy literature." Mary Corran has written "Cooper's scholarly knowledge of legend, and skill in drawing together all the complexities of the five books into a triumphant finale, produce an epic of great power. There are differences in quality in the novels--Greenwitch...is perhaps the weakest, and The Dark Is Rising and The Grey King the strongest; Silver on the Tree, while suitably life-affirming in its conclusion, is slightly preachy, but that is a natural hazard of the subject matter. Cooper deals with the innate antagonism between mortals and immortals impressively, and in The Grey King reaches great heights as she mingles the worlds and peoples of legend and the present day. The sequence is a remarkable achievement, and Cooper's gifts for description and characterization provide additional