In her The Dark Is Rising series, Cooper creates two basic character types—contemporary human mortals, and ageless figures drawn from ancient British mythology. In The Grey King Will Stanton is a normal modern boy, as well as the last-born member of a small select group with special powers, the Old Ones. In The Dark Is Rising, Will celebrates his eleventh birthday in the manner usual with his family, but he is also initiated into the group of immortals whose number includes King Arthur and Merlin the Sorcerer. Merlin in his last manifestation as Merriman Lyon is Will's teacher. Through him Will learns to step in and out of time whenever he likes, to exercise control over natural phenomena such as fire, and to prepare himself to do battle with the dark forces of Evil. He and the other Old Ones are the Light who have been opposing the Dark since the world began.

Will is at once an English schoolboy who rides about on his bicycle and a supernatural power capable of soaring far above the planet. Cooper's writing is in itself magical, and Will is equally believable in both of his roles. The human boy has succumbed to a severe disease and has come to stay with an aunt in North Wales while he recuperates. The disease has caused him to forget temporarily the nature of his quests, and he gradually remembers what is expected of him. He develops as a boy and as an Old One, and becomes confident enough of his powers to work more independently.

In North Wales, Will finds a special assistant, Bran Davies, the albino son of a Welsh shepherd, Owen Davies (or so Bran believes). Bran's colorless hair and skin stand out in marked contrast to this community of dark-haired, dark complexioned Welshmen. His eyes are those of a cat or an owl. Made to feel an outsider all of his life, he gradually learns how much of an alien he really is. It is revealed that he is the son of King Arthur and Queen Guinevere brought back into time by the Light to bear his part in the war against the Dark. Guinevere appeared with baby Bran in her arms quite suddenly before Owen Davies' cottage, lived with Owen a few days, and as suddenly disappeared, leaving Bran to be reared as the shepherd's son.

Now twelve years old, Bran meets a stranger on the mountain one day, who tells him to expect Will's coming. Bran has a white dog, Cafall, which has also been called from the distant past where he was King Arthur's favorite hound. Will's quest in North Wales is to find a golden harp that will awaken the Six Sleepers, ancient warriors now lying dormant in a mountain cave. Information for that quest is in a poem that he has memorized. The poem also mentions a "raven boy"; Bran's name means crow in Welsh, and he comments that many of the people named Bran in the Welsh legends were linked with ravens. As the novel progresses, Bran develops from a resentful outsider in this mountain community into a confident young person aware of his powers and of the role he will play in the struggle with the Dark.

Cooper offers vivid depictions of the inhabitants of this isolated Welsh farming community. Most of the half million speakers of Welsh, the largest group to make daily use of a Celtic language today, live in North Wales. Cooper has been praised by critics for her skill in presenting their bilingual speech. Her portraits of those living in the shadow...