With MaddAddam, Margaret Atwood’s imposing speculative-fiction trilogy – spanning a decade that has seen at least a few of her predictions from Oryx & Crake and The Year of the Flood prove eerily prescient – comes to an end. But while it shares much with the first two volumes, including a familiar cast of characters and a time-shifting narrative structure, this third volume is distinctly muted by comparison. The overblown surrealism and recourse to hard science in the earlier books are here replaced by a far more grounded and reflexive meditation on humanity.

It bears noting that MaddAddam relies on close familiarity with Atwood’s carefully crafted world. The novel’s introduction is a helpful refresher, but hardly sufficient for the uninitiated.

In the earlier novels, Atwood sketched the rise and demise of the dystopian society she dubs “the chaos,” using a speculative-fiction approach to critique the emergent and perilous possibilities of modern science, the increasing commercialization of society, and runaway environmental degradation. The isolated and shell-shocked lives of Jimmy (in Oryx & Crake) and Toby and Ren (in The Year of the Flood) served as vehicles for exploring a mosaic of flashbacks that cobbled together a picture of a doomed, dystopian planet.

In MaddAddam, the principal question changes from “How did we get here?” to “Where do we go now?” The story picks up exactly where The Year of the Flood left off, with Ren and Toby, former members of the God’s Gardeners eco-activist group, reunited with the kidnapped Amanda and the hapless Jimmy, who has unwittingly become a prophet for the Crakers, a childlike race that sprung from mad scientist Crake’s eugenic experiments. Soon joined by the remaining members of the MaddAddam collective, who have also – far too conveniently – survived “the waterless flood,” the group must try to stay alive and rebuild some semblance of community.

The plot is principally driven by the quotidian struggles of the ragged group of survivors, and Atwood’s treatment of the post-plague world is MaddAddam’s greatest strength. Narrated primarily from the point of view of the middle-aged and magnificently humane Toby, the stories of the group’s everyday challenges – protecting crops from the hybrid, bioengineered pigoons; staving off depression and scavenging medical supplies – are surprisingly absorbing.

Atwood treats her imagined future with a – relatively speaking – realistic touch stemming from science-based speculation. Indeed, MaddAddam might well be set in the depopulated thought-experiment described in Alan Weisman’s The World Without Us (albeit one home to genetically spliced animal species). And, while Atwood maintains a sense of unease and ominous violence throughout, this is not a doomed, nihilistic world like that of Nevil Shute’s On the Beach, nor is brutality the only game in town, as in Cormac McCarthy’s sanguinary The Road.

The book’s cast of fragile and conflicted protagonists improves on the previous volumes’ approaches to character development. There is none of the overly emotive depiction of Toby and Ren’s lives, or the borderline laughable portrayals of Jimmy and Crake’s teenage boyhoods. The ragtag survivor community of MaddAddam is more convincing. So too is the development of the Crakers, whose unplanned and unforeseen longing for origin myths and creativity makes them seem, for better and worse, more human.

On the other hand, Atwood’s insistence on following the flashback-laden method relied on in the previous volumes is far less effective here. Not only does it add little in terms of sci-fi creativity, but the focus on Zeb, the survivors’ de facto leader, is, for all his alpha-maleness and bawdy humour, simply not interesting. The flashbacks slow down the plot and, by tying up virtually all the loose ends from the previous books, leave very little to the reader’s imagination. Moreover, while the first two books glinted with the sharp edge of Atwood’s astute social satire, here the sardonicism is largely dulled.

This is not, however, to reject the validity of Atwood’s underlying arguments. The lessons we can take from her work, including simple ones about treating other creatures – humans as well as flora and fauna – with a modicum of respect and justice, being wary of the creeping medical-genetic-industrial complex, and thinking through the consequences of short-sighted liberal do-gooderism are even more pressing today than when Oryx & Crake was first released.