Scenes from Firefly - Whedon's spaceship "Serenity" shown below. (Fox)

As he delivers notes to Nathan Fillion, the strapping actor who plays the Serenity's captain, Mal Reynolds, Whedon looks notably less than strapping -- and more like a frazzled grad student who missed laundry day. ("Write 'doughy,"' he suggests, hovering over my reporter's notebook. "Write 'jowly."') But his schlubbiness is a bit of an act, concealing a charismatic, prickly intensity. After one successful take, he jumps up with a cry of "Sweeeet!" then murmurs: "Don't give him coffee! You don't know what he will become." Between scenes, he edits scripts for "Buffy" and its spinoff, "Angel." Like more than one ex-nerd of my acquaintance, Whedon compulsively peppers his speech with self-deprecating asides: "Oh, my God, I am a hack," he moans as we watch Fillion, his thumbs hooked in the belt loops of his skintight slacks, swagger back onto the ship's bridge. But like his show's hero, Whedon exudes confidence. 

And why shouldn't he? After all, Whedon has created one of the most intelligent, and most underestimated, shows on television. Like the Serenity, "Buffy" might look at first sight like a disposable toy, something cobbled from materials that most adults dismiss out of hand: teen banter, karate chops and bloodsucking monsters. Before the show went on the air in 1997, executives at the fledgling WB network begged him to change the whimsical title, arguing that the show would never reach intelligent viewers. But it did. "Buffy" is about a teenage girl staking monsters in the heart, but her true demons are personal, and the show's innovative mix of fantasy elements and psychological acuity transcends easy categorization. Despite being perpetually snubbed at the Emmy Awards, "Buffy" has become a critics' darling and inspired a fervent fan base among teenage girls and academics alike. The show's influence can be felt everywhere on television these days, from tawdry knockoffs like "Charmed" to more impressive copycats like "Alias."

"Firefly," which began its run this Friday on Fox, is an opportunity for Whedon to build a fresh new mythology, what he calls a "drama with landscape." Audaciously combining two more neglected juvenile genres, westerns and science fiction, the series began as Whedon's most experimental yet -- until Fox rejected the pilot and forced him to whip up a more accessible premiere episode. But although the new season opener has a kickier and more commercial structure than the meditative pilot he originally devised, Whedon was able to maintain his central vision. Yes, it's a space show, but it's also an intellectual drama about nine underdogs struggling in the moral chaos of a postglobalist universe. Adventure and ethical debate are melded in one sexy package. "It's about the search for meaning," he explains. "And did I mention there's a whore?" 

As technicians nudge a glowing white spaceship into the sky, Whedon talks about his frustration with those who mistake his creations for guilty pleasures. "I hate it when people talk about 'Buffy' as being campy," he says, scarfing takeout chicken with a plastic fork. "I hate camp. I don't enjoy dumb TV. I believe Aaron Spelling has single-handedly lowered SAT scores." But despite these inevitable misreadings, Whedon's heart will always be with genre fiction. Like Buffy herself, genre fiction is easily undervalued, seen as powerless fluff. But Whedon finds it uniquely forceful: using its vivid strokes, you can be speculative, philosophical -- and create stories that are not merely true to life but are metaphors for a deeper level of human experience. "It's better to be a spy in the house of love, you know?" he jokes. "If I made 'Buffy the Lesbian Separatist,' a series of lectures on PBS on why there should be feminism, no one would be coming to the party, and it would be boring. The idea of changing culture is important to me, and it can only be done in a popular medium." 

Joss Whedon's family has worked in television for generations: his father wrote scripts for "Alice" and "The Golden Girls," while his grandfather worked on "The Donna Reed Show" and "The Dick Van Dyke Show." But in many ways, Whedon says, his deepest influence is his mother, Lee Stearns, a high-school teacher who wrote novels during her summers, novels that were never published. "She was very smart, uncompromising, cool as hell," he recalls. "You had to prove yourself -- not that she wouldn't come through if you didn't, but she expected you to hold your own." 

His parents divorced when he was 9 (a "good divorce," he says). He lived with his dad, but he spent summers with his mom and stepdad at an artists' commune in upstate New York. As a teenager, Whedon attended a private boys' school in England; he became "the world's biggest Sondheim freak" as well as an avid comics fan. But at Wesleyan University, his sights narrowed to film. "I'd go out and see three classic films, stagger home at 2 a.m. and then watch whatever was on HBO," he recalls. "It was glorious." Majoring in film and immersing himself in women's studies, Whedon became convinced that the pop genres he loved -- sci-fi and horror movies among them -- could be more than just entertainment. They could carry subversive ideas into the mainstream. 

After college, Whedon drifted out to Los Angeles. An eccentric wannabe auteur with bright red hair down to his waist, he fiddled with weird projects like a musical parody of the Oliver North hearings; despite his father's industry connections, he had disastrous pitch meetings. Then he got his big break: a staff writer's job on "Roseanne." By the time he left, he had a solid writer's rep. For several years, Whedon worked as a bored but well-compensated script doctor, contributing to good films ("Toy Story," for which he received an Oscar nomination) and many bad ones ("Waterworld"). But he had an escape plan in the works, a screenplay with a mission statement. Whedon wanted to create an iconic female hero, but also "a world in which adolescent boys would see a girl who takes charge as the sexiest goddamn thing they ever saw." His mother died in 1992, but they had talked about his "Buffy" screenplay, and, he says, she knew he was on his way. 

Then, in a classic Hollywood tale of disillusionment, he lost control of his screenplay -- only to see his vision of "populist feminism" turned into a schlocky comedy. He recalls sitting in the theater, crying. "I really thought I'd never work again," he recalls of the experience. "It was that devastating." But in a second chance few get, Whedon was able to resurrect "Buffy" on television, restoring the show's powerful central metaphor: adolescence is hell, and any girl who makes it through is a superhero.

Joss with some of his Buffy stars: Left to Right  - Amber Benson (Tara), Joss Whedon (Genius), Michelle Trachtenberg (Dawn) and Nicholas Brendon (Xander).

With each of Buffy's six television seasons, Whedon's reputation grew. The show took startling structural risks. There was the silent episode, "Hush" -- a virtuoso spook show with wordless scenes as witty as any dialogue. In "The Body," Whedon broke television taboo by treating the death of Buffy's mother with raw, mournful realism. In the fifth-season finale, the heroine herself died, a scenario that managed to resonate as both a beautiful Christ-like sacrifice and an act of suicidal despair. Last season featured her painful resurrection -- she literally dug herself out of a grave -- as well as an exhilarating all-musical episode, "Once More With Feeling." (The soundtrack comes out on Tuesday.)

Over time, the show's mythology has become as rich and multilayered as any work of literature -- eternally complicating its own notions of morality, allowing characters to grow up in a way rare for television and generating enough internal allusions to fuel its own media-studies department. Indeed, several academic anthologies focus on the show; other high-flown analyses appear on "Slayage: The Online International Journal of Buffy Studies."

The show's daring and complexity have earned it many smarty-pants fans, from those who contribute to the show's insanely challenging Internet discussion groups (some of which feature posts from Whedon himself) to Ira Glass, the host of the radio program "This American Life." 

Television creators like David E. Kelley and Aaron Sorkin may be better known, but to many critics, Whedon is the more original artist, one who has been unfairly denied prizes and high ratings. To J.J. Abrams, creator of "Alias" -- a show about a tough female spy -- Whedon is a pioneer, stubbornly resisting the pressure to take the easy route to cultural respect. "He's not the normal adult in any way that I can see," Abrams says. "He's the mischievous kid and the wise-adult kid in one package. You know, if he wanted to be taken seriously in the conventional way, he could write a medical show or a legal show. But he cares more about telling stories he wants to tell, and he's being taken seriously on his terms. It's like the title 'Buffy the Vampire Slayer': if you don't smile, you're not going to get the show anyway." 

The messy anteroom to Whedon's office at Mutant Enemy, his Los Angeles production company, is filled with "Buffy" memorabilia and piles of videotapes. On the walls hang glossy framed posters: "The Matrix," "Written on the Wind," a pen-and-ink drawing of Mickey Mouse hanging by a noose. Whedon hands me a snapshot of a fellow redhead with a wicked grin; it's his wife, Kai Cole. "The funniest woman I've ever met," he says. On their honeymoon, Whedon scribbled the names of "Buffy" characters in a notepad. And it was on a long-overdue London vacation with Kai that Whedon found the inspiration for "Firefly." When the jet-lagged couple read through the night, Whedon dived into "The Killer Angels," Michael Shaara's fictional recreation of the Battle of Gettysburg. "I thought, That's the show I want to make!" he recalls. "It was about the minutiae of the soldiers' lives. And I wanted to play with that classic notion of the frontier: not the people who made history, but the people history stepped on -- the people for whom every act is the creation of civilization. Then again, there's also gunfights and action." 

From this blueprint, Whedon has built a show that, like "Buffy," twists comic-book structures into novel shapes. It's science fiction, but there are gunfights instead of laser battles, and no alien foreheads to be seen. "This is my first nonlatex show," he tells me, grinning. "The show is set 500 years in the future, but humans are still acting worse than any monster." It's a character-rich drama, but one full of violence and slapstick comedy. And while "Firefly" contains plenty of Whedon's favorite TV-friendly tropes -- whip-smart caper plots and ricocheting sexual subtext -- the show has a grubby, realistic look to it, quite unlike the shiny suburb of Sunnydale on "Buffy." Such juxtapositions can seem at once down to earth and charmingly weird. As the Serenity drifts through space, it's accompanied by twangy music right out of a Civil War documentary. "I want viewers to equate the past, the present and the future," Whedon explains, "not to think of the future as 'that glowy thing that's distant and far away."' 

And woven into the action, there's a juicy (and prescient) political allegory. At Wesleyan, Whedon was deeply influenced by his professor Richard Slotkin, the creator of the theory of "regeneration through violence": the notion that frontier myths allowed conquerors -- including the pioneers of the American West -- to rewrite bloody history as heroic fairy tale. "Firefly" is set in just such a postimperialist universe, after China and America have formed a corporate supergovernment, the Alliance. In essence, it's Coca-Cola as the White House. Our heroes are post-Reconstruction crooks scraping by on the serrated edge of the law, and depending on which way you turn the moral prism, they might resemble an antiglobalization cadre or followers of an outer-space jihad. In the show's first episode, Captain Reynolds taunts a drunken Alliance member with the Confederate refrain "We shall rise again," and the implication is clear: these characters may be underdogs, but whether they are heroes (even to themselves) is a loaded question. 

But as with Whedon's other shows, "Firefly" is as much a character study as it is an abstract debate. The ensemble includes a courtesan, a thug, a preacher, a rich-boy doctor, a tomboy engineer and a psychic. They are all archetypes with inner lives. Leading this crew is Mal Reynolds, who is, like Buffy Summers, a singularly thorny pop creation: a mordant, dark-humored fellow with bile boiling just beneath the surface. (Think Han Solo, only with more interiority.) His former enemy is now his government, and frankly, he's not coping well. When Whedon cast Nathan Fillion, he encouraged him to watch John Wayne films, aiming to help him capture elements of Wayne's physical grace as well as his dark undertones. 

"Mal's politics are very reactionary and 'Big government is bad' and 'Don't interfere with my life,"' Whedon explains. "And sometimes he's wrong -- because sometimes the Alliance is America, this beautiful shining light of democracy. But sometimes the Alliance is America in Vietnam: we have a lot of petty politics, we are way out of our league and we have no right to control these people. And yet! Sometimes the Alliance is America in Nazi Germany. And Mal can't see that, because he was a Vietnamese." 

The show's other central concern diverges intriguingly from Buffy's universe, where fate and destiny loom large. "I'm a very hard-line, angry atheist," Whedon says. "Yet I am fascinated by the concept of devotion. And I want to explore that." (His existential revelation arrived during an adolescent viewing of "Close Encounters of the Third Kind" -- an experience soon followed by a reading of Sartre's "Nausea.") Mal tells the preacher who is a passenger on his ship, "You're welcome on my boat; God ain't." If Buffy is the chosen one, forced to struggle with a responsibility that comes from outside, Mal is defiant in his belief that his fate is meaningless. "This is a man who has learned that when he believed in something it destroyed him," Whedon explains. "So what he believes in is the next job, the next paycheck and keeping his crew safe." It is a typical Whedonian inversion: much the way Buffy is a demon-killer obsessed with the morality of killing, Mal is a man of action frozen by his conviction that nothing really matters, a man forced to choose his morality at each juncture. "Whatever I may think of him politically, he's a guy who looks into the void and sees nothing but the void -- and says there is no moral structure, there is no help, no one's coming, no one gets it, I have to do it." 

Can Whedon bring these bleak undercurrents to television intact? If "Buffy" is any indication, the answer is yes -- but only if "Firefly" wins an audience. For despite Whedon's clout, the show wasn't easy to get on the air. The original two-hour pilot was idiosyncratic, with slow, John Ford-style pacing that thrilled Whedon but baffled Fox. He agreed to speed things up, but the network wanted other changes, like turning a married couple into flirting singles. He refused. "I wanted a marriage on my show, not 'Melrose Space,"' he says. Such prickly negotiations flashed Whedon back to his earliest experiences in Hollywood -- and left him nursing a very Mal-like resentment against the strictures of Fox, his own personal Alliance. 

Whedon discusses these frustrations with me one night over dinner. "There were so many times I thought, It's time to retire in rage and confusion," he says. "Some of this was just forgetting how difficult it is getting a pilot on the air. And some of it was hubris." He pauses to sip some chardonnay. "As I learned, pride goeth before a fall season. Or, as my writer Mere Smith put it, 'There are no atheists in Fox shows."' 

But if Whedon is expert at nursing a grudge with the suits, he is also buoyed by the recognition that he commands a deeply loyal audience. His fans have been waiting for "Firefly" with a mix of eagerness and trepidation -- and a sometimes unnerving sense of ownership. The previous eventing, at a pre-Emmy panel discussion in the lush Academy of Television Arts and Sciences auditorium in North Hollywood, Whedon was pelted with demanding questions: Why was Buffy's last season so dark? ("Oops!" he replied.) Was he spread too thin, cheating on his other shows in favor of his new creation?

Joss Whedon directing an episode of Angel

But afterward, as he crouched by the stage, these critics turned worshipful, clutching DVD's and Sunnydale High School yearbooks, their faces dented with the desire to say one smart thing to the guy who created their favorite show. "In the season finale, Xander's crayon speech -- did you mean that to have Christian imagery?" a middle-aged man inquired. A 9-year-old girl told him that she wanted to join the "Buffy" cast. And then a dewy young woman leaned forward and gripped his hand between hers, pulling him in for enforced eye contact: "I just want you to know -- we trust you. We know you know what you're doing. We know it will be great." 

Such damp effusions are the kind of thing that many television creators would shy away from. But Whedon loves it down there in the geek trenches. "That's the only reason I'm alive!" he says, placing his palms flat on the tablecloth. "We're paying homage to the same thing: the storytelling. I wanted to create a fiction that would affect people's lives. And this has affected people's lives. It's affected my life. Without it my life is meaningless." 

Atheist though he may be, Joss Whedon has a kind of faith -- in narrative passion, the kind that creates lasting loyalties. "Every time people say, 'You've transcended the genre,' I'm like: No! I believe in genre." For Whedon, fantasy inspires a visceral response that realism can't match. "Law and Order' is the most enjoyable thing in the world!" He laughs. "But I do not go through life imagining myself as Sam Waterston, breakin' a case, prosecutin' a guy." 

There are other, more ambitious TV shows that he admires, "The West Wing" among them. But Whedon is clearly not tempted to create that kind of "grown-up" show -- no matter how many Emmys he'd win. "I'm not an adult!" he says, shaking his head. "I don't want to create responsible shows with lawyers in them. I want to invade people's dreams." 

Emily Nussbaum is the "Summary Judgment" columnist for Slate.