Cooper does not approach the problem of evil philosophically, nor does she belabor abstractions. She portrays the powers of the Old Ones and the forces of the Dark as supernatural. They are angels and devils in everything but name, and the Old Ones are cast as saviors who rescue, however temporarily, an endangered world. Some critics suggest that these subjects are too weighty for a series of children's fantasies, but few readers agree.

Cooper has more than a literary interest in the war between good and evil. She was of the generation of British children who lived through the Blitz of 1940 in London, during which she lost a close friend in an air raid. Her book Dawn of Fear (1970), about children of that time, is autobiographical to a great extent and portrays the evil wrought on Britain during World War II. Further, she says that she...