Admirers of Michael Frayn have come to know that except in regard to quality he is wholly and refreshingly unpredictable. The reader of his hypnotic little book will be in no doubt whatsoever from the sixth word on that he is in the hands of a literary master-sorcerer: "Once upon a time there will be a little girl called Uncumber." Frayn's unforgettable heroine lives at a time in the distant future when all humanity is divided in two. "Some people are on the inside, some are on the outside. That's just the way the world is, Cumby," explains her father, Aelfric. Of course it is the insiders who are privileged, with their evey single need catered to by somatic drugs, three-dimensional holovision, piped sustenance - in short, everything, including an increasingly prolonged life. As for the outsiders, they can just grub along as best they can, except when needed to help sustain the inhabitants of the windowless houses. Unbelievably, however, all this is not enough for Uncumber, for she is haunted by a restless and inquisitive spirit, driven by Angst as she grows up, that refuses to be satisfied by such devices, as a love introduced and supplied by holovision. After dialing a wrong number one day, she espies a strange crude fellow speaking an unknow tongue, and, smitten by love, she sets out to find him. Here, of course, is the classic Quest, replete with peril, suffering, and elusive rapture. Even though our searcher is millennia removed, we can feel her fate is ironic, we are involved and we pay her homage for her courage in grappling with the Outside. Relentlessly entertaining as Michael Frayn may be -and this book is shot through with mordant hilarity - it is the real measure of his worth that in the end we know perhaps a bit more about human spirut and folly than we did before.