Just before dusk, 18 strangers enter a yurt on a Midwestern homestead. Peruvian tapestries decorate the walls of the large, round structure, and rattles stand poised for a ceremony.
The participants — professional men and women, ages 35 to 65 — put on comfortable clothing and set up sleeping bags, pillows and blankets. Everyone gets a plastic bucket, cheerfully colored in green, red or blue.
"It looks like a big pajama party," jokes the host, Kim.
The shaman, a North American who trained in South America for more than a dozen years, takes a seat at the front and leads the group through a conversation about what to expect.
Stay with your breath, he advises. There's no talking, no touching. Purging in any direction is a distinct possibility. The bucket is your friend.
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He dims the lights and, after intoning a prayer, pours a foul-smelling brown liquid into a series of cups. One by one, all 18 visitors bring a cup to their lips and drink.
For 40 minutes, the yurt is silent. Then the shaman begins to sing.
Around the same time, the drink takes effect. Some people cry; others belch. Several flee for the outhouse. Many reach for their buckets and vomit.
For the next four to five hours, those in the room do what many call "the work." Some take trips into their childhood memories. Others have visions: of nature, of healers, of fireworks. Afterward, they say the tea offered an opportunity to look at their problems in a new light.
"It was one of the most beautiful experiences of my life," says Fred, a kind-eyed, gray-bearded man in his 50s.
Kim and her husband, Josh, have organized about 50 of these gatherings since the summer of 2010. In that time, they've seen hundreds of people go through an experience like Fred's.
All three asked that their real names not be used for fear of prosecution. Though no one in the United States' underground network has yet been prosecuted, the liquid is on the list of Schedule I controlled substances.
The risks scare her, but the way Kim sees it, she doesn't have a choice.
"My life is not my own anymore," Kim says. "If that were to mean standing up in the face of legal action, I'd do it. ... After seeing how much this helps people — truly heals people — I'd do anything."
The psychoactive brew goes by many names. William S. Burroughs and Allen Ginsberg called it yage. In Brazil, it's known as hoasca. Other aliases include the Spirit Vine, the Vine of the Soul and the Vine of the Dead.
Its most common name is ayahuasca. For centuries, the indigenous cultures of the Amazon have brewed the plant concoction, and its naturally occurring dose of the hallucinogen DMT.
In recent years, the West has caught on. The tea cropped up in the Jennifer Aniston/Paul Rudd flick Wanderlust and the Showtime series Weeds; proponents include everyone from Sting to The Howard Stern Show's Robin Quivers.
One ayahuasca expert estimates that, on any given night, 50 to 100 ayahuasca groups are in session in New York City alone. And thanks in part to L.A.'s yen for spiritual enlightenment, and in part to its willingness to experiment with drugs, ayahuasca is incredibly popular here — with at least three subcommunities flourishing in the area. (See one local woman's account of what it's like to try ayahausca.)
Some of the same doctors and researchers who have, in recent years, gotten approval from the Food & Drug Administration for breakthrough studies involving MDMA and psilocybin mushrooms now are turning their attention to ayahuasca. Preliminary work suggests the brew could help treat depression, chronic addiction and fear of mortality.
People with less-defined diagnoses but a hunger for something missing say that ayahuasca offers something ineffable: compassion, connectedness, spirituality.
"Ayahuasca is penetrating American society, and its highly successful people, way more than any other psychedelic," says Rick Doblin, founder and president of the Multidisciplinary Association for Psychedelic Studies (MAPS), a nonprofit research association based in Santa Cruz. "The number of people who have had incredible experiences with ayahuasca, if they could all surface in the public sphere at the same time, it would be absolutely astonishing."
In a greenhouse at the University of Minnesota, Dennis McKenna walks past the cacao (chocolate) and the Punica (pomegranate), and strides straight to the back corner, where the vines of the plant Banisteriopsis have twisted around each other — and nearby electrical cords — to reach the room's rafters.
McKenna, a white-bearded professor wearing wire glasses and a denim shirt tucked into his jeans, points at one of the younger vines, a supple, green stem the width of a pencil.
"This is nothing," he says, explaining that mature plants can reach 1,500 feet and weigh several tons. "Usually, the part you use is the thickness of a finger."