Child survivors of some ecological disaster who live inside a sealed off dome city where the life support machinery is running down . . . Andre Norton takes this premise, surely as old as sci fi itself, and finds a new solution aptly suited to the child readers this is intended for. Kristie, no longer one of the really little kids, but still young enough to be attached to her pet fox, is one of the young ones lured away by a Pied Piper known as Rhyming Man. And, following his trail of nursery rhymes and his motto, "Believing's Seeing," she finds herself led to the world outside the dome, now livable again. She also discovers that she has acquired the power of telepathy, and sets out to communicate the secret of escape to her big brother Lew. Anyone who knows his way around the genre will find this thin stuff, but the Rhyming Man is clever enough to lure those on the cusp between fairytales and sci fi.