Errol Morris’ murky, evening-long epic Wormwood is the kind of true-crime documentary where you just know someone will pronounce, in the final hour or so, “For me, part of the story is that you can’t tell the story.” From the opening minutes, which imagine with a dreamer’s intensity the purported 1953 suicide of Frank Olson, a CIA operative, it’s clear that Morris and his interviewees will not come to any clear resolution. This is a story about coverups and conspiracy, one in which all the principals are long dead, one whose mysteries can’t be illuminated without some fictionalization — but that fictionalization here too often takes over. In this, Wormwood sometimes brings to mind the fervid speculation of a Seth Abramson Twitter thread, vaulting from the established facts of the case to imagining what’s likely to have gone down behind a hotel room’s closed door.

The opening titles, an eye-tickling black-and-white psilocybic spirograph, suggest the hallucinogens at the story’s heart, just as the insistent minimalist score suggests the paranoia. Olson, a biochemist specializing in biological warfare, soared out a 10th-story window of Manhattan’s Hotel Statler (now the Pennsylvania Hotel) in 1953. (Morris shows us Peter Sarsgaard as Olson taking this plunge in Mad Men slow motion, but in boxers and a T-shirt rather than a sharp suit.) The death was ruled a suicide spurred by a nervous breakdown.

Two decades later, in the wake of revelations that the CIA had illegally spied and experimented on American citizens, a commission led by Nelson Rockefeller releases a blockbuster report about the intelligence community’s abuse of the public trust. Among its findings: The CIA’s Project MKUltra, a study in mind control, had dosed citizens and operatives with LSD in its efforts to understand the manipulation of human behavior. The drug soon was cited in Olson’s death — a bad trip had reportedly thrown him into a depression, and he had then thrown himself out the window.

Morris’ film dramatizes Olson’s last days between interviews with Olson’s son Eric and journalists and lawyers who have taken up the case as a cause. Eric has spent a lifetime pressing the case, and he’s persuasive as he lays bare for Morris just why he no longer buys the LSD story. Over Wormwood’s four hours, a theory emerges, supported by damning yet circumstantial evidence, by the fact that the facts otherwise don’t add up. Eric Olson sees the MKUltra explanation as a coverup — a sloppy one, even — of an execution. His father, he believes, had been disturbed by the discovery of evidence of U.S. use of biological weapons in the Korean War, and the agency had seen fit to kill him. He points to “A Study of Assassination,” a 19-page CIA manual from 1953, that instructs agents, “The most efficient accident, in simple assassination, is a fall of 75 feet or more onto a hard surface.”

As always, Morris, a one-time private investigator, is a superb interviewer, and no documentarian so adeptly edits the testimony of his or her subjects. When Eric is talking (or reporter Seymour Hersh or several other interviewees), Wormwood proves gripping and upsetting, even despairing. Here are people caught between the truth they’re convinced of and what they can actually prove. In the final hours, Hersh, 79 at the time of filming, is especially compelling — and frustrating. He says he has been given evidence that essentially proves much of Eric Olson’s suspicions but that this evidence cannot be revealed without endangering a source.

So Wormwood remains an inquiry into a conspiracy and possible murder that cannot possibly reach definitive conclusions. That’s not uncommon in our age of Serial and The Keepers and the hilarious American Vandal. And, of course, truth itself is slippery in many of Morris’ previous films, not just the ones where he interviews proud prevaricators like Donald Rumsfeld (whose young self has an unsettling cameo here). Morris' The Thin Blue Line (1985) famously proved crucial to the exoneration of Randall Adams, who had been convicted of the murder of a Dallas cop; while critically celebrated and later deeply influential, the film was ruled ineligible for an Academy Award in the documentary category. As the Los Angeles Times reported in 1989, the documentary committee objected to its “blend of interviews, re-enactments and fetishist-like close-ups of police lights, pistols and other murder scene objects.”

Those techniques have since become the standard tools of documentarians, though few use them as adroitly as Morris. In his work, moody close-ups and stylized dramatizations have invited viewers into the contemplation of possible truths; he has deployed them with care, unlike many of the filmmakers he has inspired. Watch the first third of Netflix’s Voyeur for a pointed comparison: What do the heated fashion-spread insert shots of gorgeous models pretending to have sex add to the grubby story of peeping on the patrons of a cheapo suburban Denver motel? The answer is, nothing. They simply fill the screen when the filmmakers have nothing to document.

In Wormwood, Morris comes closer than ever to making the film that the Academy foolishly rejected in ’85 — to sometimes just filling the screen and the running time. (Wormwood, too, has been deemed ineligible for a documentary Oscar.) Morris does not have four-plus hours’ worth of reporting and revelation to share, and instead he offers fully scripted scenes that I’ve heard some critics call “re-enactments.” They’re not: They’re something more like conspiracy fanfiction, sometimes attempts to make sense of the unknowable but more often simply immersions in the paranoid milieu. Wormwood soaks us in atmospheric possibilities rather than promulgate one solution to its mystery.

Since this is Morris, these dramatizations are striking, often beautiful, an immersion into an elegantly sinister world of suited agents and grand art deco hotel bars. He musters up several visions of Olson’s plunge from that window, and some noir-touched dialogue scenes with a shady allergist played by Bob Balaban, but much of this footage is about mood. That’s to a fault: Toward the end, Morris gives us 90 seconds of one military man mixing a drink. Not long after that, we get a real-time elevator ride to floor 10 of the Statler and much lighting of cigarettes and pouring of tea. In montage, paired with the spoken words of his interview subjects, such footage is thrilling. But often here that footage stands alone, in long takes that reveal little except how hard it can be to fill six streaming episodes of 40-plus minutes each. In Morris’ hybrid experiment, mixing nonfiction and its opposite, the proportions seem off: The fiction simply isn’t as interesting as the documentary material. It invites us to hang out in the headspace of conspiracy theorizing while illuminating little new about it.

Advertising disclosure: We may receive compensation for some of the links in our stories. Thank you for supporting LA Weekly and our advertisers.