It is a dark and sticky night as the headbangers begin to shuffle into the Alltel Arena. It's like a trailer for "Dawn of the Dead." These Arkansas zombies want their metal, and this is the last gig in North America before Metallica leaves for its summer-long European tour.

Outside, the venue blazes with lights, a beacon in the murk, and clouds of exceedingly intense bats dart around the loading docks occupied by the 15 trucks and six buses that ferry the band's elaborate stage set, lights, speakers, pyrotechnics and roadies from town to town. The drivers are smoking butts and drinking coffee. It is quiet. Too quiet.

At the security post, a guard halts a reporter and barks into his walkie-talkie, and eventually a band aide appears bearing a plastic backstage pass picturing a winged angel of Hell in roped bondage, issuing a voiceless scream of rage or agony. On it are the words "Metallica 2003-04."

Oh, gentle reader, there was a time, in the past two decades, when a backstage pass to a Metallica concert was a thing of myth, a portal through the gates of rock-and-roll Valhalla into a feast of excess, where the Jagermeister flowed like a river and the groupies lined the hallways like pretty presents on Christmas morning, just begging to be unwrapped, and the world's most commercially successful metal band partied with the kind of reckless, petulant intensity that earned their famous moniker, "Alcoholica," which they embraced with a slurred scowl.

Those days are way over.

Down the freshly mopped fluorescent halls we go, turn left, turn right, and there is drummer Lars Ulrich, the Danish-born tennis prodigy who co-founded Metallica in 1981, looking fresh and toned, like he just returned from one of his daily five-mile runs. He is a short man with short hair, and wearing shorts.

"You're the reporter? Cool," Ulrich says and gives us a smile and his trademark little smirk. "Listen, I've got a few things to do, but make yourself at home, and I'll be back in a bit. Have some food."

Into the inner sanctum. The band's room. A table is laid with catered gourmet. Lead guitarist Kirk Hammett mumbles hello. He looks like the Count of Monte Cristo, the one in the movies, his black tresses gelled and glossy, perfect. With a ringed pinkie raised on a serving fork, he carefully spears a floret of steamed broccoli, which he plops upon a bed of brown rice. He sits beside his personal assistant, eating in measured bites. You can almost hear his arteries whistling a happy tune. We talk about his horse ranch in Northern California. The fresh air. The lure of the land.

Something is missing here, and it is a bar. "Ten years ago? At the height of the unhealthiness? There wouldn't be any food. There would have been a lot of booze, and that's what we were always worrying about: Do we have enough booze?" This is later, from lead singer and co-founder James Hetfield.

Now, Hammett contemplates his whole grains. Across the room, two of Ulrich's young children watch a "Shrek" DVD and play with toys, watched over by a nanny. Somewhere down the hall, the band's traveling chiropractor, whom they call "the witch doctor," leads crew members through a yoga session. One of the security entourage, with a shaved head and tight jeans -- a biker version of Mr. Clean -- eyeballs us. He waves us over and whispers: Shhhh, could you wait in the hallway? "This is their quiet time."

This is the band whose first album, in 1983, was "Kill 'Em All." If you didn't know the tumultuous, emotional changes these gods of metal have been through, it would not compute. "Quiet time" and "Metallica" would not have appeared in the same sentence. Until three years ago, when the wheels flew off the wagon, and the cameras began to roll.

You can learn all about it in the improbable, appalling and strangely stirring new documentary "Metallica: Some Kind of Monster," which opens in Washington on Friday. It's part Oprah, part "This Is Spinal Tap" (the classic spoof of metal bands), part insightful exploration into creativity and relationships. Two years of group therapy, compressed into 2 hours 22 minutes of film. It is a train wreck, lurid and mesmerizing, and you cannot take your eyes away from it.

On the Edge

Early in 2001, Metallica limped back into its San Francisco studio to record its first album of original songs in five years. The band was running on fumes, in danger of becoming a nostalgia act, like Kiss but without the Kabuki makeup and platform shoes.

The band members, bitter and feuding, spoiled, self-obsessed and filthy rich, were as distant from one another as planets. Trapped in a time warp, Metallica was a group of aging lizard kings whose emotional development appeared retarded by celebrity and their cult status.

This was a serious problem, a business problem, for Metallica over the years has been a cash cow -- in the top five of Rolling Stone magazine's Rich List, with a gross of $40 million in 2004.

As they assembled again in the winter of 2001, from their ranches and mansions, bassist Jason Newsted -- who had replaced Cliff Burton after he died in a bus accident while on tour with the group in Sweden -- quit the band after 14 years.

Desperate to save a sinking ship, Metallica's management company, Q Prime, brought in Phil Towle, a $40,000-a-month "performance enhancement coach," a wheedling "how does that make you feel?" therapist right out of central casting.

As Towle began "shrinking" the band (he's neither a psychologist nor psychiatrist), one of those remarkable moments in documentary filmmaking occurred. Joe Berlinger and Bruce Sinofsky arrived to shoot what was envisioned as not a movie but a kind of corporate film, or more accurately, a long-play infomercial that would be sold to a cable outlet like VH1 or MTV or Showtime to market Metallica's new (and at that time still unwritten and unrecorded) album, "St. Anger."

Serendipity. The documentarians had first hooked up with the band in 1996 when Berlinger and Sinofsky made "Paradise Lost," about three Metallica fans from West Memphis, Ark., who were charged and convicted of the ritualistic murders of three children. The crime is shrouded in mystery and controversy -- the filmmakers suggest the West Memphis Three did not commit it -- but it morphed into one of those schlocky Jerry Springer debates about the influence of heavy metal on America's youth.

But here is the thing: When Berlinger and Sinofsky started rolling film for the new documentary, they didn't know, nor did the band members know, what lay ahead.

The movie begins as a typical VH1 "Behind the Music" episode. The band members are cranky, they're struggling with some new songs, they've got some history, they're middle-aged, they're talking with their therapist. You're thinking about walking out of the movie.

And then Hetfield rises from his couch in the studio, and walks out the door. Not a word of explanation. Just disappears.

Into rehab. Off-camera for months and months. He returns -- and this is the best pitch for 12 Step programs you can envision -- a changed man.

The cameras keep rolling, for 715 days, for a total of 1,600 hours of film.

'A Totally Different Place'

Before the Little Rock concert, Hetfield pulls up a metal chair in a sterile, empty room and sits for an interview. He is a large and powerful-looking man, with tattoos on his muscled shoulders. He wears his short blondish hair swept back, and sports black-framed eyeglasses and a goatee. He looks like a beatnik and speaks candidly, without hesitation.

He likes "Some Kind of Monster," but admits it is "embarrassing" to watch. "There is the top layer, like 'This Is Spinal Tap,' for real. But below that, you see we're trying, and then you can figure it out, and all these personalities, like puzzle pieces," Hetfield says.

"The movie shows, here's the struggles, here's us pretending to be human in this completely inhuman career. People pump you up to these giant idols and expect you to be jumping off tables in restaurants, and when you don't they're disappointed in you and all the struggles you go through. The movie itself is trying to show a human side of us.

"I'm 40 and I feel like 40 now. But in the movie I still looked like I was 17. Those were the survival techniques I learned as a kid. Rage for me was a big addiction. So ugly, man, like a volcano. We're in a totally different place than we were two years ago. It's tough to explain; can't say at the end of the movie, 'They're better now.' " He pauses. "Not that we're ever better, any of us."

As for his long career as a metal man, Hetfield says he has no regrets. "The things I did that hurt myself, it got me to where I need to be now, and all happened for a reason."

But then he amends. "I do regret the wreckage on the road. The people I treated with such soullessness . . . the cheating, destruction, just completely abusing people, being drunk. I do wish I hadn't hurt other people."

Back in the wild days, "there was total disregard for anybody and their authority, no respect for any security people, total objectification of women, just degradation, that was enough. . . . Playing music was fun. But I went on the road for that other stuff. . . . I could say three little words: Rush the stage. And people would die. It's a lot of power and I used to not give a damn."

Later, Ulrich remembers, "Ten years ago? You probably heard of Sweet Sweet Connie," the famous rock groupie who lives in Little Rock. "She would be here. We'd be running around giving out passes to as many scantily clad women as possible, having parties and all the stuff you do when you're 22 years old. But as you grow older, some of that stuff gets shallow. Now it's great to have kids on tour, family on tour."

Does Ulrich miss the old days? "Nah," he says. "I access my memories. Sometimes it's fun to sit around and tell stories. Especially to the next generation."

He reminds us that it was only Hetfield who was out of control, who went into rehab. "Me, Kirk and Rob can still have an alcoholic beverage with the best of them, maybe not every night, but we can still fire it up with the youngsters, as we call them."

Upon his return from rehab, Hetfield set strict rules. He could be in the studio only four hours a day. He feared falling back into old patterns. But his changes set off some of the most memorable confrontations in the film, when he and Ulrich are literally screaming in each other's faces.

"I now realize that I barely knew you before!" Ulrich spits. It is like a married couple going at it -- you don't want to hear it, it's really ugly and dumb. But there you are, with your ear to the wall, listening.

Anger Management

The opening act, Godsmack, has just finished its set, and the band comes rushing down the hallway, past the inner sanctum of Metallica, and you can smell their sweat, like a high school gym on a Texas night. They look high from the performance and the crowd, and for a minute Godsmack looks to be the ghost of Metallica past, their younger, crazier selves, with all the lessons to be learned ahead of them.

One by one, the Metallica members move to the tuning room, where they whale away on their instruments, limbering up, kicking off the rust.

Out they come, and assemble. Hammett throws himself down on the cement and does three dozen push-ups, stands and squeezes his biceps. Robert Trujillo, the new bass player, emerges, his long black hair misted with water so that when he gets onstage and swings his head in guitar-god style, the lights catch the flying drops.

Then Hetfield, who moisturizes a new tattoo on his shoulder of a tricked-out Impala. And last, Ulrich. They're surrounded now by their personal assistants and security. They stop and huddle, heads together, hands held, and you can't hear what they say -- a metal man's prayer?

Then they burst into the arena, into the roar.

The arena is packed to the rafters, 15,000 fans, more men than women, wearing black T-shirts and jeans. They stand for the entire show. It is not the kind of music that sways the hips. You don't dance to heavy metal. You raise your arms and make the sign of the devil's horns and nod your head up and down. For hours.

But something very different is going on these days. In years past, Hetfield would spew curses, throw beer at the crowd, taunt and hector. Now? Between songs, he shouts, "Metallica is with you. Are you with us?" The crowd whoops. "Metallica is here to make you feel better. Metallica is alive and well and very grateful to be in Little Rock, for all our friends who stuck with me, during the rough times."

Later, Hetfield asks who in the audience has the band's new album, "St. Anger." Thousands of fists pump in the air. Anger, Hetfield says, "I always got a little bit of it stored up, and I bet you do, too. And this is the best place to leave it!"

And so the circle turns. Metal has always been not party music but the music of anger, alienation, rage, the darkest corner of Teen Nation. Metallica's catalogue is filled with songs of death, destruction, killing. Now? It's therapy.

"Why are these people here? Not because they need idol worship," Hetfield says earlier. "They identify with the lyrics and we connect with that, the broken parts of life. So we're going out there because of the struggles I've been through. I never thought it could be so satisfying. Onstage, I can be honest, I can tell them I'm in a really down mood tonight. And they? They can help me out."

Metallica frontman James Hetfield: "The movie shows, here's the struggles, here's us pretending to be human in this completely inhuman career."The band in a huddle before taking the stage in Little Rock. "Some Kind of Monster," a documentary about Metallica's travails, premieres here this week.Bassist Robert Trujillo, Metallica's newest member, goes simian as James Hetfield warms up behind him; drummer Lars Ulrich, right, has a pensive moment. Singer-guitarist James Hetfield, shown here in the documentary, returned from rehab a changed man. "Rage for me was a big addiction," he said.