The idea at the heart of the new Netflix docudrama series Wormwood is not that people sometimes lie, or that people in government sometimes lie, or even that people in government sometimes lie in complicated, overlapping half-truths, non-truths and truths by omission.

“The problem here is that there will never be 100 percent certitude,” says an attorney, late in the six-episode series. Adds the individual, who had been involved in various stages of the six-decade investigation into the death of Frank Olson: “People have died. Records are gone. Memories are hazed. People have reasons not to disclose. The best you can do is: What’s the most plausible story?”

Indeed, the idea at the heart of Wormwood is that truth is ephemeral, and more so over time.

The CIA—a federal agency whose biblical motto, “And ye shall know the truth, and the truth shall make you free,” is emblazoned on the floor of its Langley, Va., headquarters—gave Olson a dose of LSD without his knowledge. Ten days later, Olson plunged to his death from the 10th-floor window of a New York hotel.

Those facts are fairly well-established. Almost everything else about Olson’s death, though—whether it was intentional or accidental, whether he killed himself or someone else killed him, why the CIA may have had reason to want him dead, whether he was in his right mind at the time—was initially hidden and has decayed over time despite a lifelong, Diogenes-like pursuit by Olson’s family.

In April 1953, the CIA began a covert project known as MKUltra that experimented with alcohol, amphetamines, hallucinogens and other drugs to develop techniques for mind control. As strange and fantastical as that sounds today, the United States was trying to keep up with Soviet scientists who were already trying to find chemical combinations that would make someone into a sleeper assassin or force them to reveal secrets.

The CIA experimented on some people—including Olson, a civilian scientist who worked at an Army-run research facility—without their knowledge. Soon after the CIA secretly gave him a dose of LSD, Olson was paranoid and depressed. He told his boss he wanted to quit his job. His wife knew something was wrong. Ten days later, he was dead. The authorities termed it a suicide.

The part about giving Olson hallucinogenic drugs did not come out until the 1970s when his son Eric Olson, by that time a Harvard-trained psychologist, hired lawyers to pursue it. The CIA admitted the existence of the MKUltra program, and President Gerald Ford formally apologized to the Olson family in the Oval Office.

“We’re the only people in the whole history of this country who ever got an apology from the president in the Oval Office for the unintended consequences of some government policy,” Eric Olson says during the show in one of many interviews with Wormwood director Errol Morris. “How often does that happen? Zero. It doesn’t happen.”

The CIA drugged people. It was an extraordinary revelation. In the wake of Watergate, it was a cleansing revelation. And, as Wormwood explores in elliptical passes over the layers of facts that became known or suspected over time, the admission may have been an incomplete albeit shocking “truth” offered to cover up the fact that the CIA actually murdered Olson to prevent him from revealing details about the biological weapons he had helped develop and that the military had secretly deployed during the Korean War.

I’m not revealing too much to say that Wormwood is frustratingly inchoate. We don’t know with any certainty the circumstances of how Frank Olson (played by Peter Sarsgaard) left the 10th floor of a New York hotel room in the middle of a November night in 1953. The truth has not set the Olson family free; it has been a competitive sport that they’ve essentially lost by attrition to the CIA.

The federal government didn’t stop lying in 1953. Donald Trump lied during his first 24 hours in office about the size of the crowd at his inauguration, and he has told so many lies big and small in the year since that it’s easy to chalk up to the thing presidents do. Bill Clinton lied about Monica Lewinsky. George Bush lied about Iraq having weapons of mass destruction.

Those things were not just lies but are today regarded and accepted as lies because of the work of prosecutors and journalists whose job it is to find the truth, by the open-records and special-prosecutor laws that give them the tools and protections to do it, and by the diligence of millions of people who—often against their own instincts—don’t simply believe what they’re told because they identify ideologically with the person saying it.

The Mueller investigation of Donald Trump has already yielded the indictment of Paul Manafort, the former chairman of Trump’s presidential campaign. There are facts pointing to illegal conduct by Trump, members of his family and the people around him. Michael Flynn, the president’s former National Security Advisor, has pleaded guilty to lying to the FBI and presumably did so to avoid much more serious charges by cooperating with the investigation.

Trump’s “fake news” propagandizing has tilted the news toward a posture that his followers often reject reality based on which news organization is reporting it, and the Republican “and still I did nothing” Congress have done nothing to disabuse him, lest it endanger the tax cuts that their billionaire donors demand of them.

Trump partisans are already criticizing the Mueller investigation as a “witch hunt.” In 2018, Trump could fire Mueller by nudging the ostensibly independent Justice Department to do so; after all, Trump has nudged its antitrust division to oppose AT&T’s acquisition of Time Warner because he dislikes CNN, but not (or not yet, at least) Disney’s acquisition of 21st Century Fox because he likes Rupert Murdoch.

We’re not yet one-quarter the way into Trump’s four-year term. The things we’ve learned in those 11 months are alarming, and the things we do not yet know could be even more so. Will Mueller discover those things? Will some investigative body 20 or 50 years from now discover them? Will anyone?

If there’s a lesson in Wormwood, it is that truth is not a sprint. It’s a marathon.

Wormwood is available for streaming on Netflix.