Dr. Friedrich Ritter was in the throes of an agonizing death, his limbs rigid, his tongue too swollen to speak. He had come to Floreana, in the Galápagos Islands, four years earlier, in 1929, to find paradise. Now he sat upright with an ecstatic expression and reached out toward his companion, Dore Strauch. “I could only gaze and gaze upon him as one who sees a miracle,” Strauch wrote in her 1936 memoir, Satan Came to Eden. Ritter fell back onto the pillows and died.

Margret Wittmer, their neighbor on the island, had a rather different take on Ritter’s final moments. “Hearing [Strauch’s] voice, he sat up, looking like a ghost as he tried to pounce on her,” she wrote in her 1960 memoir, Floreana. Ron Howard’s Eden, which premieres at the Toronto International Film Festival today, considers both interpretations. The dark comedy-thriller, which is inspired by the true story, stars Jude Law as Ritter, Vanessa Kirby as Strauch, Sydney Sweeney as Wittmer, and Daniel Brühl as her husband, Heinz.

Friedrich Ritter and Dore Strauch on Floreana, 1932.

Floreana was accidentally discovered in 1535 by a Spanish bishop named Tomás de Berlanga. He dismissed it as a place “full of very big stones … the earth that is there is like slag, worthless, because it does not have the virtue to create a little grass.” The island was a stopover for pirates and whalers until Ecuador’s annexation of the Galápagos, in 1832. Through the early 1900s, several settlements were quickly built and then abandoned, including two penal colonies that ended in violent uprisings. “Most, if not all, early attempts at colonization ended in disaster one way or another,” says Francisco Dousdebés, a Galápagos guide for more than three decades.

The social and economic upheaval of World War I, combined with the 1924 publication of naturalist William Beebe’s Galápagos: World’s End, brought a number of utopians to the islands. Ritter, who worked in a hospital’s hydrotherapeutic unit and idolized Friedrich Nietzsche, was convinced that he needed to leave Germany—and his wife of more than a decade—to attain Eden. He wanted to live off the land, make what he needed with his own two hands, and go far from the chaos of civilization.

He found a new girlfriend—and acolyte—in Strauch, a married multiple-sclerosis patient 15 years his junior and a fellow Nietzsche devotee. According to Strauch, Ritter’s “astonishing blond mane, youthful bearing, [and] steel-blue eyes” allowed her to overlook the “strange absence in his face of any trace of amiability” and a personality of “extreme aggressiveness.” Before leaving for the Galápagos, Ritter removed all of his teeth and purchased a pair of steel dentures. Although he packed medical supplies, he refused to include morphine. Their new life would teach them to overcome pain through willpower.

“I could only gaze and gaze upon him as one who sees a miracle.”

When they reached Floreana, in the summer of 1929, Strauch recalled that an “atmosphere of extreme desolation enfolded [the] scene, and was increased by the almost completely dried-up, lifeless vegetation.” Meanwhile, Ritter, as he described it in a December 1931 Atlantic article, found Floreana to be “the world of a poet’s fantasy” and an “exotic picture seen through the meshes of a silken veil.”

Near a natural spring at the foot of the Cerro Pajas volcano, which has the island’s only fertile soil, Ritter and Strauch made their home. They called it Friedo, a portmanteau of their first names, and a play on the German word Friede, or “peace.”

For Strauch, island life was “another Book of Job.” Frequent droughts shriveled their crops, which were their only source of sustenance. Ritter’s tenderness dried up, too. Strauch lavished her affections on animals, including a donkey named Burro who was abandoned by an unsuccessful group of German settlers. Meanwhile, Ritter was piqued by Strauch’s mobility issues and frequent illnesses. He performed several procedures on her—including extracting all her teeth—without painkillers.

Daniel Brühl, who plays Heinz Wittmer, and Sweeney on the set of Eden.

Cologne residents Heinz Wittmer; his five-months-pregnant wife, Margret; and his teenage son, Harry, arrived on the island in August 1931, seeking refuge from the economic hardships of post–World War I Europe. They set up a home near another spring, and christened it Olympus. In her memoir, Margret recounts meeting the short, stout Ritter, who had a “fanatical” gleam in his eye, and Strauch, who attempted to “prove her erudition” by quoting Nietzsche and Lao Tzu.

“Caveman life” on Floreana, as Margret put it, came easier for the Wittmers. More interested in practicality than Utopian ideals, they had an impressive set of skills that included carpentry, construction, farming, and sewing. Heinz also brought guns, which later led to the accidental shootings of both a family dog and Burro.

The five Germans lived in relative peace for nearly two months, until Austrian-born Eloise von Wagner Bosquet, who claimed to be a baroness, arrived, accompanied by three lovers. Von Wagner, who is played by Ana de Armas in Howard’s film, introduced herself to Ritter and Strauch by presenting a packet of their mail, which she had already opened. She demanded the Wittmers show her their spring, then proceeded to wash her feet in the family’s drinking water. Shortly after arriving, she announced her intention to build a luxury hotel on the island.

When they reached Floreana, in the summer of 1929, Dore Strauch recalled that an “atmosphere of extreme desolation enfolded [the] scene, and was increased by the almost completely dried-up, lifeless vegetation.”

Carefree and charismatic, with a flirtatious smile, von Wagner commanded the lion’s share of attention from the press and visitors, including a millionaire yachtsman who made her the star of his short film, “The Empress of Floreana.” The baroness charmed the governor of the Galápagos into granting her 2,500 acres of the island on which to build her home, Hacienda Paradiso, which was near Olympus. Meanwhile, the German couples had received 50 acres apiece.

As a winter drought plagued the island, Floreana’s springs slowed to a trickle. Arguments intensified between the Wittmers and von Wagner. Tensions erupted when Ritter accused the baroness of intentionally shooting a visitor in the stomach during a hunting expedition. He wrote a letter to the governor, demanding her removal.

Shortly after, von Wagner supposedly paid a visit to Margret, who was alone with her infant. “Friends of ours have come, and we’re going to Tahiti with them,” said von Wagner. “I hope that’ll be a better place to realize my plans.” Two days later—without any ships stopping by the island—the baroness and one of her boyfriends vanished, along with some of their possessions—but not von Wagner’s prized copy of The Picture of Dorian Gray, which she reportedly never traveled without.

According to Margret, upon hearing the news, Strauch “danced for joy” and served celebratory sweets. Strauch, who later spotted the baroness’s damask tablecloth in the Wittmers’ home, was convinced the family murdered von Wagner, with help from one of her scorned lovers. Months later, the mummified corpse of the lover was found shipwrecked on nearby Marchena Island.

To survive the drought, Ritter said he and Strauch, both vegetarians, had to eat their chickens, which had been afflicted by a “strange sickness” they attributed to having fed them preserved pork. The couple ate a spoonful apiece, along with vegetables. Over the ensuing hours, Ritter developed symptoms consistent with foodborne botulism. Strauch, who never fell ill, waited until the next day before alerting the Wittmers. By the time they joined her at Friedo, Margret recalls in her memoir, the doctor could muster only the strength to glare at Strauch and scribble, “I curse you with my dying breath,” on a piece of paper. He was dead within a few hours.

Strauch returned to Germany four months later. The Wittmers remained on Floreana. The family amassed their fortune by opening the island to tourism, creating hotels and tour companies.

While there are many conspiracy theories about what happened to von Wagner and Ritter—that Ritter conspired with the Wittmers to kill the baroness and her boyfriends, or that Strauch was the mastermind behind a plot to make them disappear—current residents are tight-lipped. Today, the Wittmers are still “a powerful family in Floreana and the Galápagos,” says anthropologist Esteban Ruiz Ballesteros.

When Margret died, in 2000, she took the truth about the deaths with her. She dedicates a few dozen pages to the baroness’s exploits in her book, which is otherwise filled with memories of mountains scaled and tribulations overcome. “We had no major worries,” she wrote, “and the small daily ones were amply made up for by the peace and tranquility we now had in full measure. We were the island’s only permanent inhabitants, and no one disturbed us.”

Eden premieres at the Toronto International Film Festival today

Robin Catalano is a freelance writer whose work has appeared in The New York Times, BBC Travel, National Geographic, and more