The first season of USA’s mystery-thriller The Sinner told the story of a seemingly normal woman, played by Jessica Biel, who snaps and stabs a random person to death. It’s only through the dogged detective work of Harry Ambrose (Bill Pullman) that the exonerating truth behind the violent crime comes to light—and that truth is as much of a release for audiences at home as it is for the characters on-screen.

Each season has dived deeper into Ambrose’s psyche, revealing the complexities in the somewhat broken yet endlessly empathetic detective, all the while inviting viewers to peer into the brink alongside him. Season 2 explored his troubled childhood as it connected to a deadly poisoning at a cult in New York’s Hudson Valley, pitting Pullman against Carrie Coon’s cult ringleader with questionable intentions. Season 3, which aired its finale last night, twists the knife deeper into Ambrose’s vulnerability, as the murder suspect (Matt Bomer) is able to weaponize Ambrose’s empathy against him.

Over the course of three seasons, Pullman’s Ambrose has fully become the show’s main character, a grounding force who’s tasked with solving a strange new crime each season. Amidst the show’s twists and turns, Pullman wasn’t necessarily expecting that the biggest would be his rise to prominence (“I wasn’t needy. I wasn’t like ‘Wow, it’s going to be about me,’” Pullman says).

Pullman, who is perhaps best known for uniting mankind against an alien invasion in 1996’s Independence Day, intentionally doesn’t cut quite as confident a figure in The Sinner. As Ambrose, he’s somewhat squirrelly, and always seems as though he’s debating whether or not he should say… well, anything at all. At times, given all his hangups and mannerisms, Ambrose is a bit frustrating to watch, but the detective’s peculiar way of inserting himself into bizarre crimes results in a deeper experience than your average cop procedural. Season 3—especially its finale—takes The Sinner to some very upsetting places, but Pullman says he finds catharsis in the darkness, with the ultimate humanist message underneath.

“I think it’s been gratifying to see, even in these times, that people are following a dark story,” Pullman says. “I was thinking ‘This could be terrible for people who are watching, to watch something this gritty.’ But it’s almost like [having] strange, disturbing dreams that allow them to exorcise their own sort of demons when watching.”

GQ spoke with Pullman about The Sinner, developing a character over time, and turning to another of his famous roles for some pertinent advice.

GQ: What do you think makes The Sinner different from other crime shows on TV?

Bill Pullman: There’s quite a bit more use of guns on other shows. Even when guns come out on The Sinner, there’s not a lot of gunplay—shooting at people and ducking and running around, shooting back, you know. It’s more about watching all the nuances of human behavior and how it can present in ways where you can’t draw conclusions at first glance.

How did you make Ambrose more than just another “Difficult Man”—because there are certainly no shortage of characters like that on TV?

That’s a good way to summarize it. He is a difficult man. He’s somebody who is clearly not the macho, “I’m gonna fight crime and expose bad guys” kind of thing. He does have a lot of empathy for people; that’s surprising, because he can seem so isolated. You can see all the ways in which he doesn’t look like the kind of cop who would be successful. He’s a loner, he has a lot of stubbornness, and even the fact that he’s still doing it when most people would get out of it. He hasn’t finished what he senses is his compelling interest in still being a detective.

Do you sense that there’s something about The Sinner that feels especially relevant to culture today?

There’s a great humanism underneath it all. There’s a sense that lives are important, that bad behavior—sudden behavior—comes from a recognition that we are all sharing certain things, both good and bad, and what it is to be human. Then you have this kind of greater sense of empathy for all of us. That’s maybe a slight difference. It’s a nuanced thing. Shades of grey, which is sometimes not everybody’s choice. They want black and white in 55 minutes, and then over.

Season 3 really subverts what audiences have grown to accept as The Sinner’s formula, because for the first time, the suspect really is as dangerous as they initially appear, and Ambrose finds himself in over his head. What was playing that switch like for you?

It was part of a philosophical discussion with [show runner Derek Simmons] along the way, even in the first two seasons. Is there some shadow side that we have inside us that manifests so dark and deep in people that’s very difficult to identify? Some sort of Teflon that’s keeping them from having their deeds attributed to them? [Matt Bomer’s character] Jamie’s ability to move and behave—maybe because he’s so asymmetrical and doesn’t identify himself as a criminal— makes it so difficult to build a case against him. People can go through life for a long time before they have consequences they have to pay. There are people out there who need things revealed to them that they haven’t been aware of themselves. Some are very aware that they’re dangerous, but they don’t know why they’re not in control.

How have you noticed Ambrose changing over the course of three seasons?

In the second season, there was his inability to contain his anger as he risks being more vulnerable to other people. He’s trying to keep himself from going off of the rails. In the third, he’s up against this person who has said, “you’re a lot like me, Harry Ambrose, in more ways than you’re willing to admit. You’re angry and you’re going to act out on that,” and somehow that is being unlocked in that relationship with Jamie makes things very dangerous, because there’s a sense that violence is going to come out.

Do we need more Ambroses in law enforcement? The world?

I think there probably are some out there. I’ve run into different detectives over time. They are the ones that I think are very intrigued by the process. There’s something about Ambrose’s ability to keep working the problem that is a real strong suit. It takes a certain kind of personality to keep working the problem. Certain kinds of people in science are like that — there’s something that they can’t stop thinking about. We need more Ambroses in many different professions.

With the world at a standstill in the wake of coronavirus, do you have a sense of where The Sinner’s next season stands?

That’s still in the works, and now probably more than ever because of all this production that got arrested and isn’t happening. They probably already would have started in the writers room, and they can’t [because of the coronavirus]. All those things are still in play, but there’s a lot of ambiguity about a lot of things, and that’s one of them.

Before I let you go—what would America’s greatest fictional president, Independence Day’s President Whitmore, have to say to the nation during this pandemic?

[Laughs.] That hasn’t been said already? People have been sending me references to President Whitmore—to fight this alien thing that has come at us. I think there’s definitely the challenge of trying to pull the world together now is a whole different package than it was then. The challenge is to recognize truth. It’s now become so situational. I think he’d try to appeal to that.

Aliens would almost be easier.

I think so. At least it’s an external enemy. What we’re wrestling with as a country is definitely more challenging.

This interview has been edited and condensed.