Filmmaker Erik Nelson served as executive producer on Werner Herzog's critically acclaimed documentary Grizzly Man (2005), which chronicled the life and death of self-appointed wildlife activist Timothy Treadwell. Now, the two men switch chairs for Nelson's fascinating and harrowing new documentary A Gray State, opening in limited release November 3.

The enigmatic subject of A Gray State—Iraq War veteran, conspiracy theorist, and would-be filmmaker David Crowley—is very different from Grizzly Man's deluded naturalist, and the film's suburban Minnesota setting is far removed from the isolated wilderness of Alaska. But the rich thematic real estate the two films explore is surprisingly and disturbingly similar: it is the peculiarly American delta where individualism, paranoia, and the craving for celebrity all run together to form a dank and murky psychological swamp. It is a place, as we learn from both films, where intelligent and talented young men can be seen obsessively chronicling their own tragic descents into madness and self-destruction.

Let us begin, as Erik Nelson's interest in the case did, at the ending, with some facts that are in far less contention than alt-right conspiracy theorists would like us to believe. On January 17, 2015, police discovered the bodies of 29-year-old independent filmmaker David Crowley, his 28-year-old wife Komel, and their five-year-old daughter Raniya, all shot to death inside the Crowleys' home in Apple Valley, Minnesota. Police also discovered the family dog alive inside the house, an Arabic phrase scrawled on the wall in Komel's blood, and more than 22 TB of files and videos contained on multiple hard-drives. Left unfinished was David Crowley's cinematic magnum opus, Gray State, a feature-length dystopian "warning" about a looming government police state.

The police investigation concluded that David Crowley had shot his wife and daughter, and then turned the gun on himself. It is, of course, an explanation rejected by the sub-section of the Internet to whom Crowley—on the basis of a self-financed trailer for Gray State viewed over 2 million times on YouTube—had become a cult celebrity and a prophet of doom. To them—the lurkers in the darkest, most paranoid, conspiracy-riddled corners of the Internet—Crowley had clearly been silenced by repressive government forces who desperately feared the message he was about to unleash on the world. ("I don’t give a crap about credibility at all," one of these Crowley "truthers" says in the documentary. "Credibility means nothing to me. What I care about is truth.")

But the mystery director Erik Nelson explores in A Gray State is not one of shadowy hit-squads and secret government cover-ups. Rather, Nelson's project is a more personal and disturbing one: he seeks to understand how a young, clearly intelligent, highly talented American man went so very, very wrong. Nelson has interviewed Crowley's friends, family, and fans, and he has waded through the truly staggering amount of digital material Crowley left behind: not just scenes from his eternally unfinished feature, but also his elaborate plans for the film, his endless jeremiads about the impending collapse of society, and a steady, compulsive, self-obsessed documentation of seemingly every aspect of his own life.

What is remarkable about the documentary is the way Nelson—with a bare minimum of authorial interjection or viewer handholding—assembles all of this material into a fascinating and increasingly unsettling chronicle of a progressively disintegrating mind. Where Herzog (an executive producer here) might have been tempted to philosophize existentially, Nelson remains a silent and invisible presence throughout his film, allowing us to draw our own conclusions from the vast and often discordant information. There is art—and even wit—in his clever assemblage of this unwieldy material, but he wisely eschews easy answers and deliberate interpretation in favor of a purer form of documentary. Thus, A Gray State has the feeling of a found-footage horror film, in the very best sense. Though there is far more subtle craft to Nelson's construction than this description implies, it feels a little like he dumps a box of broken glass and bicycle chains on us, and then asks us to reverse-engineer a man's soul out of it.

And what emerges is a portrait not of a dark prophet of a dystopian future, but of a troubled figure—and a tragic family—teetering on the perverse and precarious fault-lines where self-invention, self-importance, and self-destruction meet. Nelson lets Crowley speak for himself, at length, in his own obsessively-captured words—and yet there is a curious absence of genuine substance to any of Crowley's ideas. One comes out of the other end of this harrowing descent into his mind without much of a grasp on his nightmarish vision of the future, a maddeningly convoluted intersection of theories about peak oil, FEMA camps, global warming, the UN, and a lot of other overlapping alt-right conspiracy theories. ("Once you get into this information, there’s really no end to it," he says, in one of his many self-interviews. "It just leads into the next conspiracy, and the next conspiracy.") But none of it ever makes sense in any way that Crowley can really articulate, and we start to wonder if it eluded him as much as it eludes us. (Nelson lets the tape play out to the point where we can hear Crowley almost admit that. "I guess I’m rambling," Crowley mutters to himself in resignation. "I got nothing. What’s the next thing?")

As we watch Crowley document his own struggles to realize the vision of his monstrously amorphous project (and meet the demands of his increasingly impatient Internet fan-base), we begin to suspect that his entire life was so performative—in ways he probably didn't even realize—that he was always teetering, Travis-Bickle-like, on the surface of a desperate but dangerously shallow form of insanity. A Gray State ultimately strikes us not just as a film about a man who went crazy, but as a film about a man who systematically drove himself crazy by trying to build a towering public figure on too soft and shifting a foundation.

Nelson's documentary makes for a harrowing, deliberately unsettling watch, but it ends up working very effectively on several levels. On the one hand, it is an unrelentingly intimate portrait of this one man, and of the family caught in a gradually decaying orbit around the deepening gravitational well of his madness. On this simple level, A Gray State is as personal, poignant, and frightening a horror movie as I've seen in some time.

But Nelson's study of Crowley's life and death also achieves a larger relevancy as it reflects on certain undercurrents of American society in the 21st century. In addition to the distinctly American soup of libertarianism, conspiracy theory, gun worship, military culture, domestic violence, and mental health issues encapsulated in David's story, Nelson simultaneously achieves a fascinating interrogation of the dark side of Internet culture and extremist fringe media. It is a culture we all know exists—one need only glance at the nearest Internet comment thread—but A Gray State peels back the curtain, revealing a shadow reality in which people exist as desperately constructed personae, and both truth and identity become subsumed in a culture of rabid hatred and irrational fear. Exemplifying this culture is the dark, repulsive figure of Alex Jones, a literal and spiritual ally of Crowley's who appears several times throughout the documentary. (It is the "people who are living in the Alex Jones world," David says, who really know what's going on.) Those of us who wonder that there is anyone who can take the frothing, transparent provocations of Jones seriously will be unsettled and horrified to witness how passionately his followers believe, and David Crowley's story serves as a terrifying cautionary tale about how persuasively toxic that brand of mass-marketed venom can be to the mind and soul.

So A Gray State becomes not just a study of one uniquely poignant story, but an important, and unfortunately timely observation of this moment in the history of Trump's America. Nelson has taken an unflinching look beneath one particular American rock, and exposed a writhing and fecund mass of crazy lurking beneath. And it is impossible to watch A Gray State without realizing that Nelson's documentary will now—ironically, but inevitably—be seen as part of the cover-up, and itself become another thread in the endless web of conspiracy theories. Provocative, honest, and uncomfortably insightful, it will no doubt provide further fuel for anger and paranoia, and inspire a thousand angry Internet comments in its wake. I strongly suspect that Nelson wouldn't have it any other way.