Timothy Treadwell, an animal lover who spent 13 summers living among Alaska's grizzly bears, emerges as a lost soul in Werner Herzog's sly and captivating new documentary "Grizzly Man." Based on Treadwell's own video footage made during annual sojourns in Alaska's Katmai National Park and Reserve, "Grizzly Man" documents his infantile affection for the bears, his seething anger at society, his raging narcissism, his paranoid fantasy life and, finally, the ridiculously sad deaths of Treadwell and his girlfriend in October 2003 -- in the maw of a wild grizzly.

Although ostensibly a documentary -- it is tonight's special event at the American Film Institute's Silverdocs festival and is scheduled to open in Washington theaters Aug. 12 -- "Grizzly Man" dovetails neatly with Herzog's lifelong creative obsessions. It is the tale of a marginal hero on a quixotic journey, struggling with romantic passion against both the human and natural worlds. Treadwell, with his wispy, blond Prince Valiant hair and a craggy face, even looks eerily like actor Klaus Kinski, the mercurial and troubled hero of Herzog classics such as "Fitzcarraldo" and "Aguirre, Wrath of God."

Treadwell's time among the bears, the appalling risks he took and his gorgeous video of them in their natural habitat made him a minor celebrity. He appeared on the David Letterman show and began to style himself as a freelance environmental advocate and activist. He started speaking, on camera, in the affected, storytelling tones of a narrator on Animal Planet.

"I came, I served, I protected and I studied," he gushes with too much self-importance at the end of the summer of 2001. But as Herzog's film demonstrates, the quality of Treadwell's service and protection was debatable. He broke National Park Service rules that required visitors to keep their distance from the animals, and his very presence among them may have altered their behavior.

As for study, it's a ridiculous conceit on Treadwell's part. He fancied himself a bear whisperer, but his end of the conversation consisted mostly of cooing "I love you's" and projecting on them human feelings and motivations. Herzog's film argues that this self-styled expert on the wild grizzly conceived of them as pets -- a dangerous mistake that earned him the ire and contempt of more knowledgeable experts interviewed for this film.

"I think he did more damage to the bears," says Sven Haakanson of the Alutiiq Museum on Kodiak Island. "Because when you habituate the bears to humans, they think all humans are safe."

Herzog has always been cagey about what he thinks of facts and truth. In 1999 he issued a little manifesto, declaring himself interested in "ecstatic truth," which "is mysterious and elusive, and can be reached only through fabrication and imagination and stylization."

And so there's a dizzying quality of serendipity about "Grizzly Man," a film larded with weirdness, filled with characters who seem too good to be true and visual themes that crop up with a magical and almost symphonic consistency.

One of the little bits of poor Treadwell left after the bear lunched on him was a hand, on which there was a watch. Herzog shows a coroner giving the watch to Jewel Palovak, one of Treadwell's ex-girlfriends. We also see a bear, in Haakanson's museum, that has had its paw lopped off by wild tourists. (A call to Alaska confirmed that there is a Sven Haakanson, and there was indeed a bear at the museum that lost a "finger," but a museum employee was dubious about the idea of wild throngs of bear-hating tourists.)

Yet Herzog doesn't manipulate truth for ideological gain. If he plays with reality a bit, it's for fun, for lyrical effect and mostly to call attention to the unseen artifice that goes into documentary filmmaking. Herzog flouts rules -- openly and honestly -- rather than break them surreptitiously.

And he always winks to make sure you notice. A grizzled back-country pilot we first see telling the story of how he discovered Treadwell's body is seen at the end of the film singing along to the soundtrack. In another scene, Herzog listens to the audio portion of a videotape that captures the sounds of Treadwell's death. Sitting opposite him is Palovak, watching as he listens. "Jewel, you must never listen to this," he tells her, and suggests she destroy the tape. What sort of documentary maker urges one of his interview subjects to destroy material directly relevant to his subject?

A clever and subversive one. Herzog doesn't just make documentaries, he makes documentaries about making documentaries. An ordinary director, in possession of a harrowing bit of sound or imagery, would be faced with a choice: Show it and risk being charged with sensationalism; or withhold it and risk being accused of glossing over the truth. In either case the viewer always feels a bit manipulated by the expectation, fear and hope of seeing something grisly. A cheap tension prevails. Herzog doesn't finesse the problem, he solves it like Alexander cutting the Gordian knot. Destroy the tape, problem solved.

Despite Herzog's deliciously pretentious, thoroughly German voice-over, despite his philosophical self-consciousness, he crafts a full and compelling character out of Treadwell's footage. Treadwell was a fraud, but innocent inasmuch as he mostly deceived himself. He was also the worst sort of animal lover, the kind that loves some animals over others and all animals over humans.

"I was troubled, I drank a lot," he tells the camera, explaining how his love of bears saved him from personal ruin. We see him weeping over the body of a little fox cub, then swearing a blue streak of vulgarity at the flies buzzing over the body. He runs his hand over some fresh bear poop and says breathlessly, "This was just inside of her." But when it comes to his nemesis, the National Park Service, his anger is so incandescent he seems capable of real violence.

Herzog, in the end, wraps it all up with some rhetorical ideas about Treadwell's legacy. There's the joy of the images he left behind, and although the argument about his impact, for good or not, will go on, the Treadwell story gives "an insight into ourselves, our nature." And that, for Herzog, "gives meaning to his life and his death." Perhaps he's parodying bad documentary writing here, because the film is much better than that.

It may even be yet another artful European slap shot against the naivete and violence that lurks in the American character. But it's better than that, too. Ultimately, it's a virtuoso exercise in storytelling, deconstruction, irony and last but definitely not least, empathy for difficult creatures -- both the Treadwells of the world and the beasts who eat them.

Grizzly Man (103 minutes, tonight at 7 at AFI Silverdocs and opening Aug. 12 at area theaters) is rated R and features profanity and disturbing situations.