'Maniac' Star Justin Theroux on Playing a "Controlled Narcissist" and Plans to Return to TV

Pascal Le Segretain/Getty Images

For Netflix's psychodrama, the actor crafted an eccentric character who has major mother issues: "We created this oddball character but tried to keep it as grounded as possible."

After accumulating three seasons of emotional baggage as the lead on HBO's supernatural thriller The Leftovers, Justin Theroux found some relief thanks to the role of Dr. James K. Mantleray, the zany scientist on Netflix's psychodrama Maniac. Theroux, 47, spoke to THR from the set of his latest movie — horror film False Positive — about how he found his character, working with director and co-creator Cary Fukunaga and if he'd return to TV anytime soon.

You've mentioned how the wig helped you get into character as Dr. Mantleray — what else was key?

It was his relationship with his mother and her being this sort of open-source therapist. There was a kind of vanity that I wanted him to have and a controlled narcissism. We just liked the idea of him having this secret under his wig that he's really balding and frail, and that he literally puts on this suit of armor every day to go through life.

How did you and Sally Field carve out the mother-son relationship?

Sally immediately wants to dig in and go into backstory and, "Oh, my God, they probably slept in the same bed for way too long" — that kind of thing. She attacks the character in a similar way that I do, which is "let's have fun discussions about what we think their relationship is like and then let's see if we can make that happen." I think he's one of those guys that's tripping over his own issues as far as father issues, mommy issues. And he has this one controlled environment, this controlled space, which is his lab, and then when she infects that, it's a terrifying prospect — the ultimate Freudian-medical mashup.

How did you prepare for the scene where the character goes blind and has this insane meltdown?

You look up hysterical blindness. It's still debatable whether it's an actual condition. I think you just pretend you can't see — it's that simple. But at the same time you're screaming because your mother's touch is making you blind. I thought it was just so funny. But I didn't want to have a pratfall in the middle of it and try to make it absurd. It was just by nature absurd, so I just pretended to believe it.

What aspect of this character did you work on most closely with Cary Fukunaga?

We talked a lot about the tone. That was the thing that we were trying to isolate. We agreed that we could have a lot more fun in the lab as long as we hewed close to the reality of it. We didn't want anything to be slapstick. So we created this oddball character but tried to keep it as grounded as possible, knowing the things that he has to do — that he has to go blind and have a tantrum. There are some funny lines but they were all coming out of a very real place, a really deep infected psychology.

Keeping the tone from going too absurd must have been a challenge. Was there any scene in which you had to pull it back a bit?

We played a lot with levels, with this hysterical blindness thing, for example. Like, am I at a 10? Is this a six? What's the volume knob? And we agreed for that scene obviously it should be an 11, as big as it wants, because when you go blind you start to panic and that induces its own panic attack. His world is falling apart. Then there were times when I wanted him to be as staid as possible because he always had to be in control, definitely of his subjects and wherever possible of his mother. But Sally would come in and say, "When I first see him, I haven't seen him in so long, so I should give him a kiss and let's make this an uncomfortably long kiss." And we did several different versions of that, where it was a really long kiss and then one that was like just slightly awkward.

After doing The Leftovers for so long, do you want to take a break from TV or would you jump back in?

I really like TV and I like the long-form storytelling. I wouldn't want to do a network 23-episode-a-year, seven-year run type of deal, but I definitely love the limited series because it's like one long extended film. It allows you to do much deeper dives on characters than you can do in a feature. I start to get cold feet when they start asking me to sign an eight-year contract because I don't think any character can stay interesting for that long. I mean, they can, but eventually it starts to become a little soapy. But there is a thing that I'm hopefully going to be starting soon, which is another fabulous character.

What TV series are you watching these days?

I've been working on this film, so I haven't been watching much. I haven't even gotten into the last season of Game of Thrones. I've been watching fluffy stuff — the wonderful half-hour light stuff like At Home With Amy Sedaris — to unwind to and that will make me laugh.

This story first appeared in a June stand-alone issue of The Hollywood Reporter magazine. To receive the magazine, click here to subscribe.