Kristie, [of Outside,] has lived all her life in a running-down city, completely domed and wholly shut off from the 'Outside', presumably long past devastated and rendered uninhabitable by nuclear war. She is obsessed with a desire to see the 'Outside', and when she gets there, with the aid of a mysterious Pied Piper, finds all is fresh and well again, with a small group of people planning a new and better world….
Miss Norton has suitably simplified her vocabulary, sentence structure and plot for younger readers than she usually writes for, but in doing so loses some of her considerable power of imaginative evocation. (p. 324)
Norman Culpan, in The School Librarian, December, 1976.