UP THE WALLS OF THE WORLD

Light-years from Earth, a vast galaxy-roving intelligence (the ""Destroyer"") is beginning to incinerate the sun of Tyree, home of a strange and lovely civilization. The Tyrenni sense-perceptions, sexual values, and modes of communication--mostly presented from the point of view of Tivonel, a young female--are the reverse of all Earthly norms. (Their highest good is nurturing a child--""Fathering."") As their sun flares toward nova, a handful of Tyrenni find a last-minute escape route in a telepathic experiment on earth. In the ensuing ""transmission,"" various members of both races wind up in new bodies in unexpected locations. Most drastically, a newly sentient computer program is able to invade the organization of the ""Destroyer,"" and to guide its programmer to itself. The design of the book is a marvel of complexity and daring; the portrayal of an alternative sexual ethos is among the finest achievements of this author's career. But there are disappointments. The mercurial, biting, fiercely controlled prose style of Tiptree's short stories is only fitfully in evidence in this first novel. The Tivonel sections in particular seem to search for lyrical effects and frequently find coy, sentimental ones. But, in the larger outline, this is Tiptree at her most brilliant. (In terrestrial life she is Alice B. Sheldon, a retired Army photo-intelligence officer and psychologist.)