Elizabeth Gilbert, In Full Bloom

If you're ever scheduled to visit Elizabeth Gilbert at her rambling yellow Victorian in tiny Frenchtown, New Jersey, and you think that the area's unmarked rural roads may have turned you around and delivered you to the wrong driveway, two sights will confirm that you're in the right place: first, the half-dozen stone Buddhas lounging in the grass around the front porch; and, second, the slender blonde who will be sunnily striding toward you, calling your name like you're old pals, introducing herself as Liz and thrusting a sprig of herbs into your hand. "Taste this," she'll command. You'll bruise a leaf between your teeth, and it'll savor of lemon, and you'll feel slightly bemused—what's this lady's deal?—but there won't be time for bemusement, because here come two cats who'd very much like you to pet them, and also a dog pawing at your knees, and your new old friend is ten steps ahead of you on the stone path to her house, and did you want a cappuccino or a latte?

Which is to say that the bewitching, headlong experience of hanging out with Gilbert is a lot like her bewitching, headlong books: fun, infectious, alternately goofy and deep, full of lovely things to eat. Eat, Pray, Love, her 2006 memoir, saw her bounding across continents, tumbling through love affairs, somersaulting into every big existential question ever asked. Throughout, Gilbert deployed her winning wit—and startling candor. She invited the reader into the upstate New York bathroom where, curled on the floor, choking on sobs, she asked God to help her quell her anguish; she cracked open her marriage to reveal its withered insides; she spoke, in the span of a few hundred pages, of her fits of rage and fear, her suicidal thoughts, her freak-outs in yet more bathrooms ("Always the bathroom!" she wrote), her urinary tract infections occasioned by an excess of hot sex. She laid bare her life—every piece of it—and millions of readers took in the view.

Gilbert, 44, had written a 1997 story collection, Pilgrims, and a 2000 novel, Stern Men, and a 2002 biography of naturalist Eustace Conway, The Last American Man—but it was Eat, Pray, Love that became a cultural juggernaut (and a Julia Roberts film), that made Gilbert a literary superstar, and that inspired a 2010 follow-up, Committed, in which Gilbert went through the whole soul-excavating process again, this time documenting the harried circumstances of her remarriage. As her loyal readers know, Gilbert found a happy ending in Eat, Pray, Love with "Felipe," the Brazilian who is now her husband (and whose real name is Jose Nunes).

But if you assumed Gilbert's next book would be another memoir that bivouacs on the best-seller lists for years on end—if you assumed, in other words, that she would plunder her private business one more time and serve it up for massive profit, endlessly reinventing her own lucrative wheel—you'd be wrong.

Instead, Gilbert has left memoir behind to dive headfirst into the gaslit era of scientific inquiry and seminal literature, of Charleses Darwin and Dickens. She has pored over 19th-century shipping manifests and 18th-century travelogues; has tiptoed, pen in hand, between the age of enlightenment, with its unearthing of nature's mysteries, to the thrilling dawn of the Industrial Revolution. She's been dampened by the spray of Tahitian waterfalls, felt the cobblestones of Philadelphia's streets press into her soles, climbed the spiral steps of the herbarium at Kew Gardens. She's pushed her fingers into woolly wealths of moss. She has mulled, from the confines of her desk, the correlations of nature, the principle that connects a grain of sand to a galaxy, to create a character who does the same—who makes the study of existence her life's purpose. And in doing so, Gilbert has written the novel of a lifetime.

Next: When the book she wanted to write was already written