Here’s what’s going to happen: In a few minutes, Shane Carruth will walk into this dauntingly cavernous auditorium, look out on nearly 1,300 people, and let go of a secret. It’s a late-January afternoon in Park City, Utah, and Carruth is at the Sundance Film Festival to premiere Upstream Color, his second film. Few in Hollywood have seen it. Until a few months ago, barely anyone even knew it existed. Yet today’s screening at the Eccles Theatre has been sold out for days, prompting forlorn fanboys to wander the theater’s parking lot, hoping for a miracle ticket. Like the people already inside, they have no idea what Upstream is about. They just know they’ve been waiting for it for nearly a decade.

The last time Carruth brought a movie here, it was 2004’s Primer, a mind-fogging, barely budgeted thriller that he wrote, directed, scored, produced, and starred in. It’s about two garage-tinkering engineers who create a device that manipulates time. The machine they build is a ramshackle box, one that’s both inscrutably complex and endearingly low-end, kind of like the movie itself. Carruth, a former engineer, crammed Primer with submerged plot points, tech-spackled dialog, and snakelike timelines, little of which make sense until the second viewing—or even the 10th. And because he shot it for a mere $7,000 in suburban Dallas, Primer lacks the garish CGI or carb-starved goon-hunks that make most modern sci-fi movies so depressingly juvenile. The awkward geniuses look real, and so does their invention. Carruth reclaimed sci-fi for the scientists, and even those who were baffled by the film couldn’t wait to see what he’d do next.

And then he disappeared.

Months passed, then years, without a new movie. Carruth’s single-entry IMDb page began to look less like the résumé of a promising upstart and more like the larky one-note legacy of a guy who’d left filmmaking for good. His disappearance made Primer’s found-object oddness all the more pronounced: In the final scene of the film, Carruth’s character signs off with an ominous voice recording, one that now seems almost comically on-the-nose. “You will not be contacted by me again,” he says. “And if you look, you will not find me.”

With Primer, Carruth reclaimed sci-fi for the scientists. Then he disappeared.

But last winter, seemingly out of nowhere, Carruth resurfaced with word of a new movie, sending film blogs and Twitter feeds into a holy-crapturous fit, the kind usually reserved for superhero sequels. Like Primer, Upstream Color was shot around Dallas in near secrecy, with Carruth again taking on most of the duties himself, serving as writer, director, composer, producer, costar, and main investor. (He won’t disclose the budget, feeling that such talk unduly dominated discussions of Primer, but he allows that it was “pretty thrifty.”) Carruth also announced plans to release the film to theaters himself, meaning that he’ll control the marketing and rollout—and that he’ll get to avoid the cavalcade of preening and promotion that most filmmakers must endure at Sundance. Until this afternoon, he’s managed to keep the film pretty much to himself.

Which is why, in the days before the festival, he began hearing the rumors going around Hollywood agencies: that Upstream was three and a half hours long, with no scene lasting more than a second. Or that Upstream was actually two movies.

Carruth has a dry, almost recessed sense of humor, yet he sounds borderline giddy when discussing all this speculation. “Keeping stuff from people in this industry,” he says, “is the most fun hobby in the world.” Nine years ago, Carruth was primed to make the leap from insular, small-scale thrillers to conglomerate-backed mall-magnets, another Bryan Singer or Darren Aronofsky or Christopher Nolan. But he found himself on an alternative timeline, and he seems happier there. “There isn’t a molecule of Hollywood that touched this,” he says of Upstream. “I quit answering the phone from anybody in LA. I thought, ‘I’m gonna use the tools that are right here. And then it’ll be in the world, and people won’t know where it came from.’ ”

A spaceship in the woods. This is what Shane Carruth sees one day, looking out the backseat of his parents’ car. It’s the mid-’80s, and Carruth—age 11—is being driven through the green-lined back roads of Alexandria, Virginia, his latest hometown. His father is an engineer, and the family goes wherever the work is, most recently bouncing between the suburbs of DC and Dallas. But because his father’s latest job is with a government defense contractor, Shane isn’t allowed to know what he does or even where he works. On this day, however, the trees open up to reveal two hulking white orbs in a distant field. They look like a pair of misplaced Epcots, and as the car passes by, Carruth notes a slight deviation in his parents’ body language, an unfamiliar motion that tells him, this place means something. “So that’s where you work, Dad?” he ventures. There’s no response. The car keeps going. And now Carruth knows he’s right. That brief, seemingly oblique exchange of information moves his father’s story forward. Because that’s all a story is, really: information. Flashes of data, some moving so fast they can barely be seen at all.

Carruth grew up in—among other places—Korea, South Dakota, and upstate New York. His father was an Air Force staff sergeant, and before settling in Texas, he and his three younger siblings spent years “changing homes, changing friends, needing to figure out our new environment,” remembers his brother John. “We had to create our own entertainment.” Carruth and his siblings would spend days hanging out in the woods or rooting around some local construction site, building dirt forts.

As he got older, he dove into his father’s trove of gadgets, making stop-motion Star Trek movies with a cumbersome video recorder. Like most kids of the VHS era, Carruth was unknowingly enrolled in a sort of stay-at-home film school, a curriculum heavy on the Amblin canon—E.T., The Goonies, Raiders of the Lost Ark—not to mention sci-fi afternoon-killers like Time Bandits and Wrath of Khan. His mom eventually landed a job at a video store, and Carruth constantly begged her to bring home the 1985 sci-fi fantasy Explorers, about three kids who, using a home computer and a lot of junk shop hardware, secretly build a spaceship in the woods.

At school, Carruth excelled at math and science—his favorite subjects—but he was often bored. He was curious and contrarian, two qualities that can make adolescence even more torturous than usual. “He’s always questioned authority, questioned ideas,” John says. “We don’t debate with Shane anymore, because he’ll debate both sides—and win both.”

Carruth eventually enrolled at Stephen F. Austin State University, earned a math degree, and embarked on a string of jobs, including a gig at Hughes Electronics, where he worked on flight simulation software. The money was good, but years later he’s hard-pressed to recall the name of a single coworker from his engineering days. It’s as if this part of his life never happened at all.

What he really wanted to do was make movies. For a while he worked nights and weekends on a novel, only to find that his writing style didn’t lend itself to prose. “I wouldn’t do internal monologs,” he says. “I wouldn’t write what was going on emotionally. And at some point I realized that if all you’re writing is description of what’s happening, you’re actually writing screenplays.”

But an early attempt at a script turned out terribly, and his first real job on a movie set, doing sound work for a local indie, proved unfulfilling. So Carruth stuck with the engineering jobs, never fully satisfied. “I was on the cusp,” he says. “I was thinking, ‘I’ve gotta pursue this. I’ve gotta figure out how to make a film.’ ”

He puts a hand to his head, feels around, and pulls back a finger covered with blood. The 29-year-old Carruth has just woken up in a hospital. He doesn’t know how he got here. Later he’ll remember driving home from an engineering job, then darkness, and then a voice telling him it’s OK to go to the bathroom. Eventually he’ll find out that one of his tires blew out, causing his car to flip over. But for now, all he knows is that there’s blood on his hand and that this is very bad. He gets up to look in a mirror and sees a monster looking back—“like the Elephant Man,” he’ll later recall. He’d always wondered what would happen if he somehow became disabled or deformed, worried he’d be unable to handle it. But seeing himself now, the fear is gone. He realizes how quickly humans adjust to their situation, how easily we acclimate. While he convalesces, he watches movies—’70s paranoid classics like All the President’s Men and The Conversation. They are films in which information is a weapon, something the characters—and the filmmakers—can withhold or deploy to their advantage. Inspired, Carruth begins writing a new script. It’s called Primer.

Ten years after he finished Primer, Carruth is surprised that people still want to talk about it. He’s 40 now, but he doesn’t look too different than when he made his screen debut, with gifted cheekbones, subtly expansive eyes, and a lithe runner’s physique. “I’ve always been anxious about Primer,” he says. “There’s good things about it, but all I’ve seen for a long time is the flaws.”

Primer’s surface blemishes—the rough sound, the sometimes harsh lighting—are especially frustrating to Carruth, as he spent months planning out the shoot, hoping to minimize mistakes. “Filmmaking is problem-solving,” says Casey Gooden, who produced Upstream and acted in Primer.” And Shane’s interested in the finest details.” Carruth took still photos to use for storyboards and created diagrams explaining Primer’s numerous spacetime complications.

Much of his preparations, though, simply consisted of him talking for hours on end with his costar, a former software company employee and substitute teacher named David Sullivan. Because of the movie’s tight budget, Carruth decided to shoot only one take of each scene—a pragmatic decision, perhaps, but also a deeply crazy one. He and Sullivan drilled themselves on their parts, sometimes meeting at a local library to recite dialog. “Our acting couldn’t be the problem,” Sullivan says. “Because there were too many other things that could be the problem.”

After shooting, the editing process devoured weeks, then months, and finally two whole years. Some members of the cast and crew lost contact with Carruth entirely. Finally, in January 2004, the movie screened at Sundance and quickly became the talk of the festival.

Part of Primer’s appeal, oddly enough, is its sheer inscrutability. The film is thick with rapidly overlapping dialog, much of it delivered at a low murmur—Altman audio at Sorkin speed. Many of the story clues are small, almost subliminal: a sideways glance, a seemingly tossed-off line, a minuscule wardrobe change. Though only 77 minutes long, Primer is packed with so many details that you want to revisit it immediately.

“From a first viewing of Primer, you’re inevitably confused, but you know that it makes sense,” says Looper writer-director Rian Johnson, who turned to Carruth for help in developing some special effects (which ultimately proved too costly) for his own time-travel film. “It’s that kind of dangerous fishing hook that can draw in a conspiracy theorist—the tantalizing notion that if you can put all the pieces together, this will add up to something.”

Primer wound up winning a Grand Jury Prize at Sundance, beating out such soon- to-be-huge movies as Garden State and Napoleon Dynamite. Everyone in Hollywood wanted to talk to Carruth. They all wanted to know what he’d do next.

From time to time he thinks about his religious upbringing. For a while, his parents belonged to a progressive, hippie-ish community called the Lord’s Chapel. The congregants met in a high school gym or at potluck dinners, where they sometimes spoke in tongues. What bound them together was a belief that they could find new truths in ancient words. It’s a universal need—to take something obscure, find patterns in it, and eventually unlock it. It’s the same urge, he’ll come to realize, that led us to invent narratives. To tell stories.

In the summer and fall of 2004, Carruth began traveling from Dallas to Hollywood. He took countless meetings with film people and at one point even developed an idea for a single-season TV drama. But after a while, he got the sense that no one really knew what to do with him.“I don’t think anybody looks at Primer and goes, ‘That’s the guy we have to get for Iron Man,’ ” he says.

“I get obsessed with little things and go down the pathway too far.”

For a while, Carruth tried writing a romantic coming-of-age story set on the high seas. But soon he began mapping out something much bigger, an epic sci-fi story called A Topiary. It’s a tale told in two parts: The opening section follows a city worker who becomes obsessed with a recurring starburst pattern he sees hidden everywhere around him, even in traffic grids. He eventually joins with other believers, forming a kaffeeklatsch-cult that’s soon undone by greed and hubris.

The second half follows a group of 10 preteen boys who discover a strange machine that produces small funnels, which in turn can be used to build increasingly agile robotlike creatures. As their creations grow in power and size, the kids’ friendships begin to splinter and they’re forced to confront another group of creature-builders. The movie ends with a massive last-minute reveal, set deep in the cosmos, suggesting that everything we’ve just seen was directed by forces outside the characters’ control.

A Topiary consumed Carruth. He wrote much of it in the Dallas suburbs, living off the money from Primer. “There’s no way I could have done that if I had a wife or a family or health care,” he says now. “There’s a way to live that is incredibly thrifty.”

While working on the script, Carruth used a 3-D computer program to design all the creatures himself. And since the movie would require hundreds of effects shots, he began visiting f/x houses to learn about their workflow and to see how he might create his own effects. He even built his own small-scale CGI system, renting cloud computers and writing code. “That’s where I lose my time,” he says. “I get obsessed with these little things. I think there’s some novel way to find a solution, and I go down the pathway too far.”

After Carruth finished a first draft of the script, he gave it to director Steven Soderbergh, a fan who had reached out to Carruth after he saw Primer. Soderbergh asked his friend David Fincher to serve as co-executive producer. With their names and their blessing, Carruth made a mock-up trailer for investors, one that incorporated some of his own effects work plus images from many of the Spielberg movies he watched growing up. With a budget in the low $20 millions, Carruth began meeting with possible backers, a process that ended up consuming yet another year.

“Nobody ever said no,” Carruth says. “It was always enthusiasm and amazement and ‘We can’t wait for this!’ Meanwhile, no money’s sitting in the account.” He kept lowering the budget, getting it down to about $14 million, but even that couldn’t secure an investor. “If this were the ’70s, people would be throwing money at him,” Soderbergh says. “It’s just a different time now.”

Finally, Carruth realized that A Topiary was a problem he simply couldn’t solve. Worried he’d be forever stuck in a loop of endless meetings and fruitless go-aheads, he walked away. “I decided that if nobody was gonna say no, I was gonna have to say no,” he says. “It sort of just broke my heart.”

It’s been a few years since Primer debuted. It has taken this long, but they almost have it cracked. A sort of community has formed. People fill up message boards and YouTube videos and multipart critical exegeses with their thoughts on Primer, picking up on each abyssal clue, building on one another’s discoveries. Carruth occasionally logs on to see what they’ve come up with, and he realizes: They’re getting it. Maybe no single individual has put together the movie’s puzzles, but together, as a group, they’re getting close. They’re finding the information and turning it into meaning.

On a gray afternoon in Park City, Carruth sits in the kitchen of the house he, his mother, and his siblings’ families have rented for Sundance. There are rows of air-drying baby bottles on the counter, not far from a still-sealed case of scotch. Empty ski lifts squeak teasingly in the sky nearby, and several reliably raucous bars sit just a few blocks away.

Sundance is a wholly customizable experience. You can choose to spend the entire week in the dark, mainlining as many movies as possible, or you can get caught up in the brand-stamped promenade of party-hard horseshit that goes on downtown. Carruth has no time for the former and no patience for the latter. He rarely ventures far from this house, save for the occasional Upstream Color screening or press interview. With the exception of the casual get-togethers he throws here with his family, he doesn’t go to a single Sundance party. “I’m not trying to foster some weird reputation of being a recluse,” he says. “But some of that stuff, it’s really not fun. I get spun up.” He covers his face, his hands forming a pair of giant spiders. “I feel my face crinkling from trying to smile and look like a nice person, when all I wanna do is go to bed or read.”

He took a similarly standoffish approach to creating the film. Carruth didn’t make any announcement when he started working on his long-awaited Primer follow-up. Only a handful of people even knew he was making it. “He wanted to keep it as quiet as possible,” costar Amy Seimetz says. “There’s something really nice about being able to work and not have to answer any questions before you know what the movie is.”

Though the movie gossip site CHUD eventually broke word of the project’s existence—and one local newspaper in Plano, Texas, even tracked Carruth down on the set—few in Hollywood caught wind of it. It helped, of course, that a lot of people had stopped paying attention to him altogether.

Like Primer, Upstream Color is a tough film to synopsize. It’s about a young woman named Kris (Seimetz) who’s abducted from a bar, drugged with a worm-derived substance, and placed under a hypnotic spell by a methodical thief who forces her to empty her bank accounts. Her life ruined, she meets Jeff (played by Carruth), who has undergone a similar trauma. Eventually, they find their memories beginning to merge and their lives becoming tied to other organisms around them, including a herd of pigs.

Upstream is dense with information, though much of it is visual. Some scenes do indeed last just a few seconds, but there are also long, crucial passages with no dialog at all. It’s beautifully baffling, a love story as fractured as its lovers, and one that takes several viewings to even begin to absorb. “I don’t even try to describe it to people,” Soderbergh says. “I go, ‘You’ve just gotta see this thing, and then we’ll talk after.’ ”

At the Eccles Theatre, right after the premiere of Upstream Color has concluded, Carruth takes the stage to a large swell of applause. It’s hard to know what anyone will make of a movie that features pigs, worms, and a smidge of gunplay—even at Sundance, where a movie called Pigs, Worms, and a Smidge of Gunplay is likely playing down the street, waiting for a Fox Searchlight deal. But when the lights come up, there are only a handful of empty seats.

Many of the crowd’s queries indicate an enthused confusion about the film, viewers gamely struggling to synthesize the movie’s flashes of data into a story. Carruth does his best to talk them through it, bracketing his thickly worded responses with rapid-fire “um”s and earnest “wow”s. The last question, though, throws him. A woman wants him to clarify some of the made-up science that drives the story—but what she’s really asking in a politely roundabout way is: What the hell did I just watch?

“So the plot didn’t land,” Carruth says. “Gotcha.” He then goes into an explanation that, if transcribed here, would count as a spoiler, albeit a thoroughly incomprehensible one. It involves pig corrals and symbiotic experiences, and by the end, Carruth himself almost seems a bit tripped up. “Does that answer anything?” he asks in mock exhaustion.

A few hours later, at a downtown hotel bar, Carruth and some of the Upstream team sip whiskey and scroll through their iPhones, looking at the initial reviews. “The sum-up,” Carruth says, “is ‘I got it, but you’re not gonna get it.’ ” (Over the next several days, the conventional wisdom will evolve from stunned praise to backlash-baiting mini-mania. A Time.com headline—“Did One of the Best Movies Ever Made Just Debut in Park City?”—aptly encapsulates the sense of bewildered awe.)

Carruth knows Upstream isn’t some four-quadrant crowd-pleaser. But he needs it to be at least modestly successful, however one defines “modestly successful” for a low-budget, self-released indie movie nowadays. Carruth says he’s ready to start another film—a darker take on the maritime romance he began almost a decade earlier—but only if he can once again finance it himself. “My ability to make another film is directly connected to whatever revenue this movie generates,” he says. “It’s not like, ‘Maybe I can buy a house someday.’ It’s more like, ‘I get to make this film exactly the way it needs to be.’ ” It is almost as if the movie already exists, as if Carruth’s role is merely to discover it. Maybe it’s what he’s been working toward this entire time. Maybe he’s just only now able to see it.

Contributing editor Brian Raftery (@brianraftery) wrote about Ian Rogers, founder and former CEO of music upstart Topspin, in issue 21.01.