Self-Reproducing Machines From Another Planet : THE FORGE OF GOD<i> by Greg Bear (Tor Books</i> :<i> $17.95; 448 pp.) </i>

Are there intelligent beings somewhere out there among the stars? The scientific community’s rising interest and intensifying debate over the search for extraterrestrial intelligence has, in the past decade, been paralleled in the literature of science fiction by a string of novels on the theme of alien contact that have ranked among the best hard SF of the period.

Now Greg Bear has joined this select group with “The Forge of God,” a first contact novel of a different kind. Bear uses an idea that goes back to John von Neumann: The arriving ET’s are self-reproducing machines sent by other civilizations. He has also turned the first contact novel in a new direction, deftly adopting the style and structure of the disaster thriller, introducing us to many well-drawn characters populating a near-future Earth that has a time bomb ticking at its heart.

The dilemma that all alien contact novels must sell is the Fermi Paradox: If there are intelligent ET’s out there, why don’t they visit, why don’t they write? Bear’s solution, like Benford’s, is that some of those ET’s have dispatched world-killer machines to deal with developing rivals that come to their attention. “We’ve been sitting in our tree chirping like foolish birds for over a century now, wondering why no other birds answered. The galactic skies are full of hawks, that’s why,” writes one of Bear’s characters after this sinister lesson has been learned.

Bear’s ET’s understand the value of ambiguity and misdirection. They plant ships resembling geological rock formations at several sites, particularly the Australian desert and California’s Death Valley, and stage different and mutually contradictory shows for the natives at each site. The Australian ship brings messengers of glad tidings, ellipsoidal robots who claim to be advance representatives of a peaceful galactic federation. The Death Valley ship contains a messenger of doom, a pink pterodon emerges speaking perfect English and claiming to have stowed away on the alien ship after it destroyed his own planet. The human investigators are very confused. And it all seems a test with no right answers.

Tappan King, editor of Twilight Zone magazine, recently observed that there are two basic plots in much of fantasy and science fiction: “The Man With a Plan” and “A Straw in the Wind.” The first presents a problem to the protagonists and follows their progress in solving it; the second places the protagonists in a situation completely beyond their control and capacity and shows their struggles, frustrations and ultimate fate. Much of hard SF falls into the former category. “The Forge of God,” as perhaps implied by its title, employs the “straw in the wind” motif, and uses it very effectively. The protagonists are swept along by forces beyond their control, behaving with admirable rationality and doing reasonable and human things in the face of an impossible situation. If there is progress toward some desperate solution of Earth’s dilemma, it is all concealed behind the scenes while the protagonists are manipulated like chess pieces. In this, Bear’s work lies closer at its roots to J. G. Ballard’s new wave writings than to the dominant John W. Campbell school of hard SF. It is a profound and unusual approach to hard science fiction, permitting great depth of characterization.

If I have any complaint about the book, it is perhaps the attenuated ending. The nature of the stunning climax is such as to leave few loose ends to be dealt with in the denouement, but even with this in mind, the ending is rather flat and schematic. There is a writerly reason for this, I suspect. There is some evidence that the author may be preparing the literary soil for the sowing of a sequel. . . .