The legend of D.B. Cooper, a mild-mannered man who hijacked a Boeing 727 taking off from the Portland International Airport in 1971 and parachuted from the plane with $200,000 in cash, endures because of the metaphoric potency of the story. Depending on your vantage point, Cooper represents freedom, rebellion, ingenuity, or the outlaw spirit. His crime, which remains the only unsolved case of air piracy in the United States, inspired novels, movies, songs, and, in David Lynch’s Twin Peaks, the name of a coffee-loving FBI Agent. He leapt from the sky straight into the cultural imagination, where he’s found a permanent home as the ultimate true crime cipher. 
 
On a fundamental level, The Mystery of D.B. Cooper, a new HBO documentary from filmmaker John Dower, understands Cooper’s appeal as a piece of American folklore, but that doesn’t mean the movie skimps on the specifics or the speculation that makes Cooper such a rewarding Wikipedia deep-dive. Dower’s approach to the material can feel scattershot: He interviews people involved in the hijacking (the pilots, a passenger, and the stewardess who lit Cooper’s cigarette), family and friends of people who claimed to be Cooper, and journalists who have sifted through the massive troves of information about the case. With so much material, it’s hard to steer the narrative. In its best moments, the movie provides an engrossing tick-tok account of the hijacking. Though some of the historical context, particularly the information about air travel and the economic climate of the ’70s, can feel surface level-just because an interview subject says “it was a different era” doesn’t mean you have to include a cliché like that in your film-the actual crime comes to life through a combination of contemporary interviews, slightly cheesy recreations, and archival footage of media coverage surrounding the event. Those stray bits of ’70s television, like a moment where flight attendant Tina Mucklow notes that Cooper was never “cruel or nasty or impolite,” have an immersive quality. 
 
The sections devoted to the possible suspects and their theories surrounding the case are trickier. Jo Weber, the widow of a man who claimed to be “Dan Cooper” on his deathbed, outlines her reasons for believing her husband committed the crime. She’s convinced, and so is the young “memory man” that assists her in piecing together her thoughts, recollections, and research on the case. But her story is quickly brought into tension with the other suspects the film introduces-Barbara Dayton, LD Cooper, Richard Floyd McCoy Jr.-and it’s apparent that Dower, tasked with “solving” a case that’s frustrated the FBI and amateur sleuths for decades, won’t be resolving that tension. He’s not building an argument that one person is more “correct” than another. He’s simply observing, using the testimonies to create a detached portrait of projection, belief, and paranoia.  
 
As viewers of Netflix’s Unsolved Mysteries reboot can attest, there’s an inherent risk in telling a story that will inevitably build to an ambiguous ending. The qualities that make the Cooper case the perfect rabbit hole to get lost in-the open-endedness, the nebulous anti-authority energy, the sense of mystery-also make it challenging from a narrative perspective. The Mystery of D.B. Cooper skillfully sketches out the details of the crime without fully capturing what makes the case so appealing to obsessives. Need help finding something to watch? Sign up here for our weekly Streamail newsletter to get streaming recommendations delivered straight to your inbox.

Dan Jackson is a senior staff writer at Thrillist Entertainment. He’s on Twitter @danielvjackson.