Eighteen years have passed since the events of Sagan's previous novel, Idlewild, in which ten genetically-modified young people, created by desperate scientists in a final effort to ensure humanity’s survival in the face of the terrible plague known as Black Ep, woke from the Immersive Virtual Reality in which they’d grown up to find themselves alone in an empty world. Not all could withstand the shock of this discovery, or the new horror of their existence, and now only six survive. Fantasia has vanished. Halloween, despairing and embittered, lives alone in North America. Isaac, Champagne, and Vashti have dedicated themselves to recreating the human race--though they’re divided by ideology, for Isaac believes the new generation of humans must be human, and stave off Black Ep with sophisticated drugs, while Champagne and Vashti work to create post-humans like themselves, whose resistance lies in their genes. Pandora, the technician, moves between these two sometimes hostile camps, still helplessly in love with the absent Halloween.

But Black Ep, endlessly mutating into ever more deadly forms, is an implacable enemy--and human nature is just as slippery, the wild card in every experiment. As the plague makes a reappearance among the precious new generation created by Isaac, Champagne, and Vashti, an outside force observes with possibly hostile intent, and betrayal threatens from within. To survive, the original group must unite--even angry Halloween. But can they overcome the scars and terrors of the past? And if they do, will it be in time?

The above synopsis, with its realer-than-real VR environment and plague-decimated world, sounds pretty derivative--and in many ways it is. Sagan avoids the trap of the typical postapocalyptic SF epic, however, by focusing on character rather than on Matrix-style adventure. There’s certainly action, with the looming menace of Black Ep and the constant struggle of combating it--but the engine that drives the story is the uneasy relationships between the characters, their strengths and failings and self-deceptions, and their sometimes fatally misguided choices. The book proceeds in short sections from several different viewpoints, a series of highly subjective first-person accounts whose unreliability only slowly becomes clear. Each narrator has his or her own distinctive voice; the other characters, viewed through their eyes, shift and change like chimeras. What’s the real story? Whose beliefs are justified? Who has betrayed whom? It’s left to the reader to put the pieces together, even at the climax. This elliptical narrative approach, as well as the deft character portraits, carry the book well beyond the overfamiliar tropes of its scenario.

As a concession to conventional suspense-building, games are played initially with one viewpoint, turning it into a sort of red herring--a piece of misdirection that seems a bit too obvious later in the book. But for the most part the tension builds organically, generated both by the inherent tragedy of the situation and by the toxic personal interactions that progressively break down the fragile defenses of the tiny community, much as Black Ep breaks down the defenses of the body. In the end a costly lesson is learned about arrogance and complacency, balanced, perhaps, by the smallest spark of hope (which is salvaged, appropriately enough, by Pandora).

Edenborn is admirably self-contained; I didn’t read Idlewild (an oversight I intend to correct), but had no difficulty picking up the story. It’s elegant SF, dark and haunting, with characters who linger in memory long after the last page is turned.