“The Earth is just too small and fragile a basket for the human race to keep all its eggs in.”

Ever since Robert A. Heinlein first made this quotable observation some decades ago, science fiction writers, futurists, and even cultists have had a crystalline motto around which to secrete their fears, plans, visions, and hopes concerning the future of the human species in the wake of some imaginable or unimaginable disaster of global proportions. Of course, even prior to Heinlein’s dictum novelists had had no trouble imagining the extinction or near-extinction of humanity, in such classics as M. P. Shiel’s The Purple Cloud or George Stewart’s Earth Abides or Fred Hoyle’s The Black Cloud. These apocalypses, however, seemed generally unstoppable by human efforts. But a new paradigm arose with the advent of the Space Age.

With the gradual spreading awareness from 1980 onward of the Alvarez hypothesis — the scientific thesis that periodic asteroid strikes could devastate the planet, as had occurred during the extinction of the dinosaurs — attention focused on this particular threat and its survivability through technological chutzpah. (Although with an eye toward retention of good hooks, disasters involving climate change, plagues, alien invasions, and nuclear wars were not slighted in fiction thereafter.)

Books like Lucifer’s Hammer by Larry Niven and Jerry Pournelle, and The Forge of God by Greg Bear (which compounded invading aliens and the antimatter demise of our planet) began to adopt a philosophy of damage mitigation and species survival through dissemination into space. As our species established, in real life, a more permanent presence in space, with various orbital platforms and speculative Mars missions, Heinlein’s imperative seemed all the more doable.

One amazing work that preceded Neal Stephenson’s Seveneves, our current exemplar of this genre, and seems a direct ancestor, is Terraforming Earth by Jack Williamson, issued by this amazing Grand Master when he was ninety-three years old. Rendered uninhabitable, Terra sends her sons and daughters off on a long, transformative exodus that spans millions of years before the home world can be reclaimed.

Williamson’s narrative occupied literally several hundreds of thousands of years, and, consequently, much was elided. Stephenson is concerned only with the next 5,000 or so years — a cosmic blink of the eye — and uses three times the pages that Williamson did, thus allowing the younger author to endow his future history with much more detail.

We start in a recognizable day-after-tomorrow milieu (female president of the USA who is not named Clinton, larger International Space Station, better robotics, etc.) and meet a panorama of characters in the kind of smooth, big-screen presentation that goes back at least as far as 1932’s Grand Hotel and came to be one of the defining features of the disaster films that achieved prominence in the 1970s. If we can arbitrarily narrow down Stephenson’s deftly diffuse cloud of narrative attention to just two characters who figure most prominently in the first 600 pages of the novel, they would probably be Doc Dubois, a media-savvy scientist who is plainly analogous to Carl Sagan or Neil deGrasse Tyson, and Dinah MacQuarie, a robotics expert.

When the story opens, Dinah is resident on the International Space Station, investigating the asteroid Amalthea, which is tethered to the ISS, and Doc Dubois is doing one of his regular fundraising gigs on Earth. Both witness the unanticipated, impossible, and horrifying destruction of the moon: some unknown “Agent” smashes Luna into seven chunks. The world panics a bit at first, but the outcome seems, while dramatic, livable. Then the experts weigh in: these seven chunks will tumble and drift and ricochet and splinter further, until they become a flock of innumerable missiles of various sizes, which will lose orbital stability and rain down on Earth, purging its surface of all life. The time frame until catastrophe is just two years.

The global population goes into overdrive to select a handful of refugees and shoot them into space, where the ISS forms the nucleus of a hastily assembled Cloud Ark. These people must perpetuate the human race for millennia, until the planet is again habitable.

The dense and hurried events of these two crucial years occupy roughly the first 350 pages of the book. (And you can bet that the phrase “all the eggs in one basket” gets explicitly cited a couple of times.) Stephenson thus has the canvas afforded by a traditional large-size novel to show us the Realpolitik workings of the doomed populace; the brilliantly explicated hard science behind constructing such a Last Redoubt and getting the people into it; and the various heartstring-tugging human dramas among those on the ISS, those left on Earth, and those who transition from one place to another. (Doc Dubois ends up in orbit at the behest of the USA president, Julia Bliss Flaherty, or JBF, who herself will figure prominently in the tale.)

The next 200 or so pages, post–Hard Rain, follows the incredible and excruciating struggles during the subsequent five years to get a stable setup in place for the long haul. Not to commit spoilers, I will merely say that not all the humans — some 1,500, the entire remaining species — are on the same page. This section is even more harrowing than the first series of events. Stephenson combines every doomed polar expedition there ever was with every victim-rich coal mine collapse and tsunami wipeout, then stirs in all the Apollo 13 disaster type stuff neither you nor I have the knowledge or ingenuity to imagine. And while his compassion for this new human condition is always on display, Stephenson is equally merciless and Darwinian. “No BS” is the cri de coeur of both the author and the survivors, because any wishful thinking leads swiftly to doom in this unforgiving environment.

One perennial attraction of this type of tale is the notion of  “getting back to basics”: the author has a chance to reexamine the necessary constituents of a society, the prerequisites for civilization, the new ethics and morals of a culture dominated by a challenge to its very survival. We sweep away all the trivial and tedious clutter and distractions of vain and hedonistic modern life and plunge into the heady, brutal ocean of do-or-die demands.

Stephenson stages such a Big Think at the end of Part Two, when the seven women who are all that remain of the race, the parthenogenic “Seven Eves” of the title, must lay down the template for what is to come: the massive leap that opens Part Three, which jumps us forward in time 5,000 years. (No spoilers here, given that this information is part of the advance publicity for the book.) Humanity is now several billion strong, living in high-tech orbital O’Neill colonies while the planetary surface is most of the way through its restoration, with some early-adopter humans nonetheless taking up residence there.

To say that this final segment of the tale, once again as long and as densely imagined and populated as many stand-alone SF novels, involves major cognitive dissonance and mental whiplash is an understatement. What we learn now is that the Seven Eves have each contributed their core characteristics, bodily and neurological, to make up seven strains of humanity, whose complementarities and rivalries drive this civilization. Stephenson does a bang-up job depicting such an odd Stapledonian future where the concept of race is real and hard-wired — simultaneously more and less important than such constructs are today. (This commentary on the present state of affairs is understated, wise, and particularly potent in light of recent headlines.) Stephenson adroitly employs every tool in the speculative writer’s suite — new vocabulary, new languages, new cultural defaults and codes — to render the post–Hard Rain civilization as colorfully and vividly as in any Jack Vance novel.

Moreover, he inserts frequent flashback sections that bridge the 5,000 years of history, telling us what happened to the Seven Eves and their closer descendants.

As for the adventure aspect of this section, it involves an almost Tolkienesque gathering of a delegate from each of the races into a “Seven,” a kind of Sturgeonesque gestalt that will go down to the planet’s surface and investigate some strange new phenomena that, again not to ruin any Big Reveals, tie back into the early moments of the tale.

In his previous books, Stephenson has sometimes flaunted an abstruseness and density of ideas that takes some rigorous parsing to fully appreciate. This book gives us something different: a transparency of style and action, a willingness to guide the reader through the most complex concepts with some gentle handholding. I think this difference in approach and tactics stems from the fact that Stephenson perceives this novel to be more than a mere story, something approaching a dramatized instructional manual. Not that he expects his exact scenario to happen, but rather by spotlighting the heroism and brains necessary to deal with this imaginary apocalypse, he can inspire his readers to face any similar crises with similar bravery and ingenuity.

In Stephenson’s ultimate future, the seven races all derive inspiration from the “Epic,” the raw audio/video footage of what happened in space aboard the ISS and afterward. It serves as their root mythology and source of “Purpose.” Might not this novel — along with other visions of apocalypse overcome — do the same for us?