The twisted, drug-fueled phenomenon that's sweeping Manhattan prep schools

It's 11:30 on a Friday, and a dozen students from Dalton, an elite Manhattan private school, are splayed out on nap rugs, munching graham crackers and sipping boxes of Mott's apple juice. Raffi plays quietly in the background, and a young woman with a maternal voice reads aloud to them from a stack of children's books, starting with The Cat in the Hat.

A few missing details:

It's 11:30 at night; the kids are on the floor of a yellow school bus that's parked not in Manhattan but a desolate lot in Williamsburg; and everyone on the bus, including the storyteller, is in high school. Oh, one more thing: they're all on 5-methoxy-N N-diisopropyltryptamine, better known as the club drug Foxy.

Every two weeks, in some forsaken corner of the city, New York's privileged teenagers go to "Sindergarten," a traveling party for 17-year olds who, for a few carefree hours, want to feel like they're five again. Nursery school-style accessories—snacks, children's music, storybooks, finger-paints—are supplemented with multiple doses of Foxy methoxy, a hallucinogen similar to Ecstasy said to facilitate a childlike sense of wonder with the world.

Since September, Josh estimates, about 300 kids have infantilized themselves at his parties, coming from as far and wide as Riverdale's "Hilltop" academies to the Berkeley Carroll School in Park Slope—and he's struggling to keep up with demandSindergarten parties are the creation of Josh (not his real name), a senior at the Fieldston School in the Bronx suburb of Riverdale. He came up with the idea last summer in the Hamptons, he says, when he and his friends were lamenting the artificiality of their computer-age adolescences.

"We grew up with the Internet, with a thousand channels on TV, with cell phones and Blackberries and iPods and all this technology," he says in a characteristic rapid-fire baritone, taking a pull from his Winston Light outside a sidewalk café on the Lower East Side. "We didn't have real childhoods. This is our way of getting back what we were deprived."

Of course, Josh gets a little more out of Sindergarten than Jungian catharsis: He charges $50 a head for the three-hour event, a fee that students from the day schools across the city happily fork over, often in groups of 10 to 15. After overhead costs (bus rental, gas, snacks, supplies, $100 payment to a scruffy 22-year-old with a commercial driver's license who rents and drives the school bus), he can clear up to $800 for a night's work.

Since September, Josh estimates, about 300 kids have infantilized themselves at his parties, coming from as far and wide as Riverdale's "Hilltop" academies to the Berkeley Carroll School in Park Slope—and he's struggling to keep up with demand. "I service whichever schools show the most interest for that weekend," he explains. Once he's set up an appointment with that school's point man (who must be referred by a fellow sindergartener), Josh discloses the location of the school bus for the night—usually an abandoned lot somewhere in Brooklyn or Queens. He arranges the environmental accoutrements and oversees the activities, but abstains from using Foxy. "I've seen a lot of friends get hospitalized for that shit," he says. When asked if he fears being held accountable for any overdoses on his bus, he becomes shrewdly legalistic. "I don't know of any drug use on the Sindergarten bus—that's idle speculation. What people do before they get on isn't my responsibility. I'm running a fully legal business." A spokesman for the NYPD said the department has never received any complaints about Sindergarten, but added that Foxy arrests and seizures have spiked ten-fold since 2005.

"We all do it," writes an 18-year-old sindergartener, Sarah, in an e-mail interview. "I wouldn't say people are addicted to it, but it'd be hard to let yourself go like that without a little Roxy [a slang term for Foxy] in your system." (Sarah, the daughter of divorced Upper East Side parents who are both active—and highly visible—on the charity circuit, was hesitant to participate in this story, and agreed to do so on the condition that we not use her real name.)

Nevertheless, nothing traumatic has happened so far, and the Sindergarten subculture is thriving. As is wont to happen with teens—even teens pretending to be preteens—a distinct lingo has sprung up: when sindergarteners hook up on the bus (a frequent event, according to Sarah), it's called "playing doctor"; whoever temporarily plays the adult for the "class" is called "teacher"; and if anyone uses a word deemed to be above the 4th-grade level, the offender must go to the back of the bus for a mandatory "ten-minute timeout." Besides "story time," their activities are varied: sing-alongs, show-and-tell, arts and crafts, and whatever games one can play inside a cramped Type A-1 sixteen-seat school bus.

On this windy Friday night in March, a girl with dyed red tresses and scuffed Uggs raises her hand. "Teacher, can I go to the bathroom?" she asks.

"May you go," corrects the cherub-faced teacher.

"May I go?" she says.

Were the casual observer to ignore the participants' ages and the telltale indications of foxy use—persistent giggling, spacey expressions, and one vomiting episode—they could easily forget that this magic bus isn't really an elementary school classroom. A boy with an unsuccessful attempt at a goatee asks if anyone wants to play marbles. Two friends eagerly hoot "Me! Me!" Three lissome girls sing "Ring-Around-the-Rosie" in the narrow aisle. Another pair plays patty-cake in their seats. An artsy-looking student with fashionable retro glasses clutches a Teddy bear—"Mr. Wayne"—and conducts a dialogue with it in a baby-voice while drawing with Magic Markers on construction paper. The illustration is of a horse, and the blue caption scrawled with the penmanship of a six-year-old reads: "Hes A pretty pony yes a pretty really itty little firey orange outstanding Lovely Shetland." One of the marbles players openly weeps after losing a "blue one" somewhere on the floor, but his goateed friend shares one of his, and the boys hug. Overlooking it all is Josh, who beams through a flop of thick, indie-rocker hair that's escaped from his porkpie hat. He looks content and vulnerable, a vastly different Josh from the cynical, disaffected young man I met at the LES café.

"They want to get in touch with those basic emotions and experiences that were absented from their childhoods. These kids have been fast-tracked since nursery school for Harvard, they grew up in the sterile bubble of Fifth Avenue penthouses, they had nannies instead of parents"Asked if he is aware of "rejuveniles," adults in their late twenties and thirties who ape the styles and cultural predilections of teens or kids, profiled in a 2003 New York Times article and subsequent book, Josh scoffs. "I've heard of them," he says. "They're kind of pathetic, don't you think?"

But aren't they the same as sindergarteners, if a bit older?

Not at all, he says, his voice assuming a fervid, almost religious, conviction. "Sindergarteners know that we're all sinners, especially once you leave childhood—and we go back to find something pure, something that cleanses your soul. 'Rejuveniles,' or whatever they call them, are in denial. To them, it's, like, being a kid means reading Harry Potter and playing kickball and stuff. In the end, they just don't want to pay their bills for a few hours or admit they have to wear a suit to their job. They don't give a fuck about the essence of childhood, which is that you're part-sinner, part-angel."

Manhattan psychiatrist David Stern has at least one teenage patient who, he says, regularly attends Sindergarten parties. "Obviously, I can't condone any activity that promotes the use of controlled substances and underage sex, but I'm not completely unsympathetic to the impulse," he concedes. "They want to get in touch with those basic emotions and experiences that were absented from their childhoods. These kids have been fast-tracked since nursery school for Harvard, they grew up in the sterile bubble of Fifth Avenue penthouses, they had nannies instead of parents. I wouldn't be surprised to see something like this take off around the country, even among the middle class."

Josh maintains the secrecy of the sindergarten phenomenon with a dictator's iron fist, but, aware of the increasing popularity of his creation, was willing to cooperate anonymously—because, he says, "I knew you'd write about it anyway. So this is, like, risk management." When the mother of a Trinity junior discovered her daughter had been sindergartening under the guise of sleepovers with a friend, she nearly alerted Fieldston to Josh's side gig—until her daughter told her that Josh keeps a list of his customers' names and has threatened to post them on the Internet if he's ever fingered. "If I don't get into college, no one does," he vows. Another strict rule is that Sindergarten is never to be mentioned on blogs or MySpace. "We have a code name," he says, steadfastly refusing to reveal it. So far the plan seems to have worked; a Google search for "Sindergarten" yields only a few results, none connected to his enterprise.

When Josh does go to college—he's applied to "several Ivies, and Michigan's my safety"—he plans to continue throwing Sindergarten parties. "This is not some stupid trend," he says philosophically. "It's a way of life. Sindergarteners know that being a teenager sucks—and being an adult isn't much better. The only time people are ever truly happy is when they're kids."

Manhattan-bred prep schoolers typically affect a wisdom beyond their years, wear outfits they hope will make them look older, and score fake IDs to sneak into bars. Despite Sindergarten's sex, drugs, and Raffi (at one point later in the evening, I'm told, two boys and three girls retreated to the back of the bus for clothing-optional fun), regression as an ideology seems to help these kids break out of their Holden Caulfield-style alienation. When this idea is suggested to Josh, he breaks into a grin.

"Dude, if Holden was around today, he'd be a sindergartener," he says. "No one in the scene's a phony."

In The Catcher in the Rye, Holden's sister Phoebe reaches for a gold ring on the merry-go-round, a symbolic gesture of impending adulthood. Here, at the end of the night, everyone exits the bus in an alphabetical, single-file line, politely thanks the driver, and receives one shiny gold star.

"May you build a ladder to the stars and climb on every rung," Josh says, quoting Bob Dylan, as he affixes a sticker to the forehead of each sindergartener. "And may you stay..."—they respond in tandem, as if reciting a nursery rhyme—"...forever young!"