One part “Blair Witch,” one part “Adaptation,” and the rest wholly unique, the startling new documentary “Grizzly Man” by the great German filmmaker Werner Herzog tells a wild tale that is as much about its director as its subject. The grizzly man is Timothy Treadwell, a childlike ex-actor who lived with and filmed himself interacting with bears out in the Alaskan wilderness. Far from your average adventure photographer, Treadwell likes to dub his bears with saccharine names like “Sergeant Brown,” and talk to them about topics ranging from his past alcoholism to his dubious sexuality. He treats the bears as equals. Traveling weaponless, he is a self-described “kind warrior,” trusting the animals with his life. “Grizzly Man,” a bizarre, challenging, gorgeous film, is all that remains of him.

With this unsettling narrative, Herzog already has a documentary film that trumps fiction, but he goes even further. He casts himself as narrator and faces off against the deceased bear lover, attempting to refute his trust of nature. Yet Treadwell makes his philosophy clear throughout the film: animals are better companions than people. Scene after scene catches him uttering his favorite communique to the bears, “I love you,” with wide-eyed conviction.

Treadwell is a problematic hero. Besides talking like a child and referring to himself frequently in the third-person, he has sudden and unexpected anger fits. He aims upsetting streams of obscenities at his own camera, words that are at odds with his normal loving self. For this troubled man, redemption seems to lie with the bears.

At the beginning of the film, watching this Willy Wonka-like explorer (Johnny Depp, not Gene Wilder) cavort around the tundra seems funny. But Herzog quickly reveals Treadwell’s horrifying demise — he was, as one might guess, eaten by a bear. After that, Treadwell’s bear-hugging takes on the eerie pallor of irony. By placing his death at the beginning of the film, in the vein of “Lawrence of Arabia,” Herzog elevates Treadwell to mythical status. Something meaningful must explain this man’s horrific end; even his slightest gestures must hold a clue to some truth about humanity. And that’s where Herzog comes in.

As the film progresses, it becomes overtly clear that the documentarian identifies with Treadwell. Herzog takes the bear lover’s incompetent filmmaking seriously, noting the grace of certain camera angles and Treadwell’s insistence on fifteen takes so he can try different bandana colors, his signature clothing item. Herzog seems to take the bear fanatic as an alter ego, a more innocent version of his own current self.

But reality gets left behind as Herzog remakes the story — and the protagonist — for his own purposes. Instead of showing Treadwell’s naive love of nature for the craziness that it is, Herzog inflates it to biblical proportions. By trying to become a bear, the film claims, Treadwell was seeking to reenter “Eden,” to become innocent once more by joining with nature.

And yet Herzog sets up Treadwell only to take him down. The filmmaker, who narrates the film himself, claims that there is no connection to be had with nature, that the world is “chaotic” and unfriendly. He is attracted to Treadwell’s argument, and at first glorifies it, but ultimately sees it as dangerous and must refute it. Thus, the most powerful argument at his disposal is Treadwell’s death, which seems to affirm Herzog’s view of a hostile universe.

As if this sort of exciting intellectual exploration weren’t enough, “Grizzly Man” is spectacularly well made. Herzog’s frames — the interview segments of the film — are crowded with things to look at, so much so that they outshine Treadwell’s amateur footage. In one particularly notable shot, thousands of bugs drone lazily back and forth in front of an Alaskan airplane pilot. He never acknowledges their existence, but they add an incredible sense of unease to the interview. Particularly unnerving is Herzog’s interview with the coroner who analyzes Treadwell’s possible last moments in exactly the same manner as Treadwell talks about the behavior of his bears.

“Grizzly Man” is unlike almost any other documentary film in recent memory. It is more interesting than any fictitious Hollywood film and it is definitely more frightening. Towards the end of the film, as Timothy Treadwell stands smiling in front of a rain-drenched camera, hours before his demise — and Werner Herzog in his thick German accent begins to see things in the frame that aren’t actually there — the film jumps the tracks and heads off, untethered, into brand new cinematic territory.