The Oscar-winning documentarian Errol Morris’ docudrama Wormwood feels like an especially timely project right now. In the new Netflix miniseries out Friday, Peter Sarsgaard plays Dr. Frank Olson, a scientist who fell to his death from the 15th floor of a New York City hotel. While the CIA takes responsibility, claiming he jumped after being administered LSD for a government experiment gone wrong, his son, Eric Olson, is not so easily convinced that the government is telling the truth. Olson spends his life trying to get to the bottom of what really happened to his father, and Morris recounts it all through a series of re-enactments starring Sarsgaard, interspersed with interviews with Olson and others who helped uncover the truth. It is a hair-raising four-hour investigation that will have you on the edge of your seat, and awed by the depth of the deceit. Here, W talks to Sarsgaard about conspiracy theories and how he prepped for the role.

Mark Schafer/Netflix

How did you jump on board for the series?
My agents were in touch with Errol, and I heard loosely what it was about, and that he was interested in having me act in it. Errol came to see me in Hamlet, and then over a period of a couple of years, we would talk about it from time to time, whenever he came into town. I’ve been such an enormous fan of his work for so long and really believe he’s always shining a light in the darkness. Whatever he was interested in having me do for this I was interested in, but he wasn’t articulating this when we started. We just figured it out as we went along.

What was it like working with a documentarian, as opposed to a feature filmmaker?
There is no such thing as a normal feature filmmaker, I’ve worked with filmmakers who have been music video directors, and filmmakers who have never done a single project in their lives but have a story to tell. There’s a lot of ways to make a movie. I just think the most compelling reason to work with someone is when people have as strong of a need to tell a story as Errol had with this one. Then I get interested, you know? And you can tell when it’s genuine. And I certainly worked on things where no one was pretending it was a passion project. When an actual passion project comes along, I say yes every time.

Eric’s life obsession was investigating the death of his father, which to him is open and unresolved. Did you go into this differently as an actor knowing that there is no conclusion?
For me the conclusion is not really my job. An actor works in the micro, not the macro. None of the scenes started with me needing to get something from the person I’m playing the scene with. There was some sort of resolution at the end of each scene and we moved on. I had to get used to acting in a different way though. I played somebody who didn’t have a lot of agency, he was mostly just led around, and believed in the government so much as to believe he might be a security risk. He believed in the system enough to believe that he was the problem. It's hard for me to wrap my mind around, especially with the politics of right now. Shooting the film, I felt it would have a lot to do with what the current situation is. The government has been lying to people for a very long time.

Would you consider yourself a conspiracy theorist?
No, because conspiracy theorist implies someone who actually knows what’s going on and thinks they do. I just know and believe that there is enormous evidence to support that actually no one really knows what the hell is going on. In some ways, we’re all being led by our desires. You can take it back to the very notion of capitalism. Why we feel we have to buy this and this and this. I would have to believe something happened differently than it did. I know the World Trade Center was hit by two airplanes and that’s what blew it up. Because I was there. I saw the plane hit the building.

Even though your character was not a security risk, he was brainwashed to believe he was the problem...
I thought he was crazy to believe he was the problem. To me it’s also a product of that time. In the early 50's, we had no reason not to believe in our government. They had done great things. I have tremendous sympathy for the way he saw the world. I remember in one scene, Errol was trying to scare me and he screamed “Trump Supporters!” as a way to try and freak me out. I think my expression was more like confusion and sadness. I’m not afraid of a Trump supporter; I’m just confused and saddened.

Were you shocked at the end at all? Were you surprised at how evil and manipulative the whole cover up was?
I would have been if it was 1950-something, but so much has happened. And I mean, we’ve had a government lie to us so repeatedly and in so many different ways, between Iran Contra, to Watergate, etc. Even the language of government is manipulative. So, yeah, I think it is difficult to bring out people’s animal instinct. To fight a war you need a certain type of aggression. To have them agree on health care you have to bring out the empathy. The government’s job is to rub people’s feelings.

Eric Olson being interviewed in Wormwood.

Netflix

How much did you communicate with Eric?
Not much. I was playing someone that he spent his life trying to find out what happened. It was just too complicated to talk to Eric about much more. I introduced myself via e-mail, and we corresponded once or twice, I basically told him that I would not need to talk to him very much. I didn’t care so much about being this actual guy. I watched a lot of home movies, but my own father worked in the government air force. My father is also a mathematician. It is having a certain view of the world and belief in certain things. It’s probably more the love for my father in my performance. Even though he definitely would never have done LSD.

Were you upset by the open-endedness?
No. But the thing I also like about Errol is that he speculates, but he speculates in so many different directions. At the end, he infers it could be this, it could be that. He’s got such a concrete and sequential part of his mind, I find him very trustworthy as a documentarian. I know he’s not going to arrive at some conclusion unless you put it there. I know there are ways he could have speculated a lot more than he did. There’s evidence of other things, and evidence that corroborates things that are in the film, but he won’t put it in there unless it meets a certain journalistic standard of being a concrete answer that we all crave.

Is there any specific advice that Errol gave you?
No, but a couple of times when we were filming, he expressed he didn’t like what I was doing. But he said it very simply and directly. The rest of the time he was more encouraging of whatever direction I was going in, which I liked. The thing about Errol is that he’ll pick up the camera and point it anywhere, he’ll have you keep acting in the scene long after you normally would have cut it. For me, he’s a delight to act for because I’m just somebody who needs variety from time to time. I could do the whole movie again and be just as satisfied, because it doesn’t have that narrative so many films have. There's a lot of room to move around and try different things.

Peter Sarsgaard's favorite cinematic sex scene involves spaghetti: