Sometimes an island paradise is actually a waking nightmare

The year is 1927 and Dore Strauch Koerwin, in her mid-20s, is a smart, curious German medical student who’s also unhappily married and recently diagnosed with multiple sclerosis. Her soul is starving, but so is the rest of her: She’s been trying to live off nothing but figs. At the pioneering Berlin Hydrotherapeutic Institute, she falls under the care of Friedrich Ritter. He’s a wiry raw-food fanatic who tells her, as men have been telling women forever, that it’s all in her head. “You are not ill, but you desire to be ill,” he says. Sparks fly; he can look right through her. Ritter is not just into raw food. He wants to “abandon the civilized world” and has recently become inspired by a group of Germans who “practiced Eastern mysticism, lived off the land, slept outside, and wore as little clothing as possible. One member wrote a ‘cook-less’ book that condemned the violence of a carnivorous diet and offered recipes, including ‘soups for the toothless.’”

In short order Ritter has his teeth ripped out (replaced with steel dentures that gleam in the sun and never quite stay in), and the two seekers have abandoned everything — spouses, families, possessions, promising careers — for an uninhabited island in the Galapagos. As Lucy Irvine made clear four decades ago in “Castaway,” one of the best modern accounts of our persistent, insistent dream of starting over in a new Eden, there’s nothing paradisiacal about a scorching, dry, buggy, unpopulated island except for the views.

Floreana, the chosen respite of Koerwin and Ritter, isn’t technically deserted. It’s crawling with rats and a horde of feral and very aggressive pigs, cows, donkeys and dogs, as well as swarms of insects. It gets little rain and has little fresh water, save a couple of trickling springs. The work is unrelenting. Food must be picked, planted and harvested, shelter built. The vegetarians are surrounded by meat, which they refuse to kill or consume. And Ritter, it comes as no surprise, is a physically and emotionally abusive jerk. The power balance has always been off; Koerwin’s self-declared purpose is to support Ritter’s writing of a masterwork of philosophical gobbledygook, which gets ever harder to sustain as he beats her and whips her amid the increasing maladies of eating nothing but fruits, eggs and an extremely limited selection of vegetables.

Through ingenuity and backbreaking work, however, they do build an enchanting, kind-of-Eden they call Friedo. A house of sorts. A shower and running tap. Gardens and egg-laying chickens, even pet donkeys that come running to Dore’s call. They spend their days naked. Koerwin’s teeth rot. Ritter doesn’t wear his dentures. Koerwin takes copious notes in her journal as her lover’s abuse deepens. Ritter taps out his magnum opus on an old typewriter. Back home the Depression hits and Hitler rises, but alone in their self-chosen isolation, perhaps they could have found a semblance of happiness.

But word got out, as it always does, and the rest of the world couldn’t leave these escapees alone. Others arrived to live among them: A German couple with a child and baby on the way. A narcissistic baroness and her two submissive male lovers. A parade of rich men on yachts — this is the most remarkable part of Kahler’s well-told story — followed, bringing reporters and filmmakers and curiosity seekers and wannabe naturalists. The castaways would grow ever more dependent on the attention and necessities and luxuries that attention brought — shovels and clothes and shotguns and books and seeds — even as that attention shattered their self-reliance. It didn’t help that the baroness, who may or may not have briefly seduced Ritter, was a gun-wielding fabulist who claimed sovereignty over the island and wanted to build a luxury hotel. The castaways, now nine, bickered, backbit and undermined one another, all as surely and swiftly as the contestants on an episode of “Survivor.”

There’s nothing fancy about “Eden Undone.” Nothing particularly poetic. Kahler could have gone bigger and deeper, plumbing the long history of yearning for escape and utopia, especially on tropical islands. I wish she’d spent a bit more time on the lives of those who ended up staying on Floreana — a triumph in the face of great odds, it would seem. But this is a good book, a story that needs no adorning. Kahler gets out of the way, letting the details speak for themselves. The sense of dread and impending violence gnaws and grows, a tragedy that makes your stomach sick even as you are compelled to turn the page. You want to shake Koerwin, Ritter and the others. Knock some sense into them! How can such smart people with such expansive dreams say and do the wrong thing, over and over, wedded to a utopia they’re loath to admit is hell?

“There was a menace in the air,” Koerwin wrote in her journal surprisingly early in their sojourn, “something sinister and frightening, the more so because there was no outward sign of anything amiss.” The thing sinister and frightening, it turns out, was them, us, all of us, and our own restless need for someplace else.

Carl Hoffman is the author of five books, including “Liar’s Circus,” “The Last Wild Men of Borneo” and “Savage Harvest.”

Eden Undone

A True Story of Sex, Murder, and Utopia at the Dawn of World War II

By Abbott Kahler

Crown. 330 pp. $32