If Jeff VanderMeer’s Southern Reach trilogy has a moral, it has to do with the dignity of the search for even partial truth. Photo Illustration by Honjo; Photograph by Russell G Sneddon / Writer Pictures / AP

The three weirdest books I read last year were all by the same writer. His name is Jeff VanderMeer, he’s from Tallahassee, Florida, and he’s the King of Weird Fiction. He writes in the genre—his 2009 novel “Finch” is a detective story, reminiscent of “Blade Runner,” set in a city divided between normal people and mushroom people—and he champions it: with his wife, the influential sci-fi and fantasy editor Ann VanderMeer, he’s edited the anthologies “The Weird” and “The New Weird.” It’s self-defeating, of course, to try and define weirdness (although VanderMeer has offered definitions). A lot of fiction, moreover, merely pretends to it, invoking its atmosphere without being, in fact, all that weird.

Still, when you’re in the presence of the genuine, uncanny article, you know. Stephen King is tremendously imaginative, but H. P. Lovecraft is weird; Kafka is probably the ultimate weird writer. In VanderMeer’s “Finch,” the mushroom people (“gray caps”) are people-shaped, and they can seem like character in an ordinary detective novel. (“You stupid fucking mushroom” a cop says while interrogating one of them. “Answer the question.”) But, standing next to one, you feel its “humid weight.” You can torture a mushroom person by pouring water on its head, but if you cut it into pieces it stays cold and dry. Gray-cap mold is everywhere; their fungal constructions grow to the size of buildings, blocking streets, billowing in the wind, and luminescing at night. VanderMeer, in short, is a genuinely weird writer.

All that said, last year, he transcended “weird.” He wrote three books—the Southern Reach trilogy—so arresting, unsettling, and unforgettable that even non-weird readers read and loved them. Broadly speaking, the novels, “Annihilation,” “Authority,” and “Acceptance,” are eco-sci-fi: they’re about researchers exploring a mysterious, deadly, and unaccountable wilderness called Area X. But they’re also experiments in psychedelic nature writing, in the tradition of Thoreau, and meditations on the theme of epistemic pessimism, in the tradition of Kafka. Often, speculative fiction betrays itself, becoming predictable just at the moment when it’s supposed to be “out there.” But the Southern Reach books make it all the way out. They imagine nature, both human and wild, in a new way. And they take a surprising approach to language: in addition to being confounding science-fiction novels, they are fractured, lyrical love letters to Florida’s mossy northern coast.

The Southern Reach novels take place in a landscape that combines the marshes of Florida with the islands of Vancouver. There, decades ago, an inexplicable environmental change occurred. A large swath of land and sea, encompassing a town, an island, and two lighthouses, was sealed behind an invisible and largely impenetrable barrier. The authorities called the enclosed territory Area X. Inside it, nature shifted. It grew wild and pristine, dense and fertile—improbably pure, as though nature had said “Enough!” and reclaimed itself.

Teams of explorers are sent into Area X. They find that the nature there is strange. The purple thistles seem unnaturally eager. The sky is too full of birds; the long grass is teeming with little red grasshoppers. Everything is too alive. The explorers feel watched by things—plants, the sky—that can’t actually watch; in a paranoid moment, one of them suggests that all of Area X could be camouflage for a single, diffuse living process or thing. Over the course of many expeditions, it becomes clear that Area X is, in a subtle way, wrong. And, also, that it has an effect on people: it alienates them from themselves and, eventually, kills or transforms them. No one knows how; the few researchers to return from Area X remember almost nothing about it. But everyone who travels there feels the potential for change. In the first book, the protagonist, an unnamed biologist who specializes in “transitional environments,” describes the feeling:

Now a strange mood took hold of me, as I walked silent and alone through the last of the pines and the cypress knees that seemed to float in the black water, the gray moss that coated everything. . . . I was no longer a biologist but somehow the crest of a wave building and building but never crashing to shore. I saw with such new eyes the subtleties of the transition to the marsh, the salt flats. As the trail became a raised berm, dull, algae-choked lakes spread out to the right and a canal flanked it to the left. Rough channels of water meandered out in a maze through a forest of reeds on the canal side, and islands, oases of wind-contorted trees, appeared in the distance like sudden revelations. The stooped and blackened appearance of these trees was shocking against the vast and shimmering gold-brown of the reeds. The strange quality of the light upon this habitat, the stillness of it all, the sense of waiting, brought me halfway to a kind of ecstasy.

“My sole gift or talent,” she later reflects, “was that places could impress themselves upon me, and I could become a part of them with ease.” It’s common, in describing nature, to describe oneself—to see, in the landscape, one’s own “rough channels.” But, in the Southern Reach books, the process works the other way. The explorers, as they venture deeper into Area X, hiking toward its stark, mysterious lighthouses, begin to merge with it. The question is, what are they merging into? What, as one researcher puts it, is “colonizing” them? (“The trees are not trees,” one man says, “the birds are not birds and I am not me.”) When the explorers finally begin to encounter the monsters in Area X, they aren’t the predictable kind: one is a deranged writer, another is a wave full of eyes. Some hypnotic property of the landscape prevents the explorers from seeing these dangers clearly, but, even if they could be seen, they wouldn’t be any more comprehensible. “You could know the what of something forever,” one researcher says, “and never discover the why.” If the books have a moral, it has to do with the dignity of the search for even partial truth.

In today’s literary landscape, it’s natural for the Southern Reach books to find themselves grouped together with the broadly ecological, post-apocalyptic stories that are now in vogue. But there’s not much that’s post-apocalyptic about VanderMeer’s novels. They’re not interested in how life ends, but in how it changes, and they are fascinated by the question of persistence through change. Reading the trilogy, the novel that came to my mind most often was Virginia Woolf’s “To the Lighthouse,” especially the uncanny section, in the middle of the book, when the Ramsays’ island home is abandoned and is overrun by plants, birds, toads, and mold. (“What power could now prevent the fertility, the insensibility of nature?” Woolf writes. “Only the Lighthouse beam entered the rooms for a moment, sent its sudden stare over bed and wall in the darkness of winter, looked with equanimity at the thistle and the swallow, the rat and the straw.”) I was reminded, too of “Upstream Color”—Shane Carruth’s recent movie, in which a couple discovers that their emotions and perceptions have been linked, through a microecology of fungi, worms, and orchids, to a group of pigs on a farm outside of town—and of “Picnic at Hanging Rock,” Peter Weir’s extraordinary film about a group of Australian schoolgirls who visit a creepy mountain and disappear. These stories are animated by a sense of hidden continuity. Concrete details stand in contrast to the presence of an abstract whole—a whole that shapes life, but isn’t wholly visible from within it. The whole seems allied with nature, but not, in itself, natural.