For music fans, there was a surprise embedded in the operatic trailer for director Peter Berg’s new Boston Marathon bombing thriller Patriots Day: a single line at the top of the final credits screen reading “Music by Trent Reznor and Atticus Ross.” The kneejerk reaction to the collaboration, from Nine Inch Nails and David Fincher devotees at least, might resemble Michael Bluth’s recurring response to Ann Veal: Really? This movie? A near-past historical re-enactment flick, with the word “patriot” in the title, starring Mark Wahlberg as a salt-of-the-Earth Boston police officer, from the director of Battleship and Afghanistan war drama Lone Survivor?

Even the PR has felt incongruent: Berg, in a recent interview following the election, said the film would hold appeal for Clinton and Trump voters alike, while Wahlberg discussed how his Catholic upbringing has allowed him to remain “optimistic” about Trump’s impending presidency. This might seem like the last project that Reznor—a guy who once wrote an apocalyptic concept album about a near-future totalitarian American government and said that Republicans shouldn’t be fans of his band—would want to get anywhere near.

After seeing Patriots Day, though, Reznor and Ross’s involvement seems a bit easier to credit. Berg absorbs the viewer into the characters’ maelstrom of desperation and grief and goes light on the moralizing; Reznor and Ross’s furtive drones and overdriven arpeggios bolster and clarify that intensity without dialing in any typical Marvel-movie Sturm und Drang. On a purely professional level, too, the high-profile gig for Reznor and Ross is also a logical culmination of the duo’s past six years of writing film music. The 51-year-old Nine Inch Nails mastermind and Ross—48, his co-musical director on all of his projects for well over a decade, and currently an official member of both NIN and Reznor’s band with his wife Mariqueen Maandig, How to Destroy Angels—are now, by any yardstick, accomplished Hollywood composers. They’ve scored four movies together since winning an Oscar for their first collaborative soundtrack, for David Fincher’s 2010 Zuckerberg bildungsroman, The Social Network; three of those have come since the release of Nine Inch Nails’ most recent studio album, 2013’s Hesitation Marks, on which the two also collaborated.

Reznor and Ross’s other soundtrack project of 2016 seems like a more apt choice for the pair: Before the Flood, October’s Leo DiCaprio-starring, call-to-action climate change doc from actor-director Fisher Stevens. The sprawling, often punishing Patriots Day score builds and shifts at a glacial pace, but in Flood, the pivots between the more muted, often-tuneful compositions come more quickly. As DiCaprio journeys from Greenland to Singapore to the White House to flipping through a book of Hieronymus Bosch paintings with the Pope (one of the odder cinematic moments of 2016), the film’s score adjusts to evoke the various endangered natural landscapes on which the movie focuses. Despite splitting duties with veteran Scottish post-rock outfit Mogwai and Oscar-winning Argentinian composer Gustavo Santaolalla (most famous for Brokeback Mountain, Babel, and Netflix’s Making a Murderer), the music retains the trademarks of a Reznor/Ross production. Small melodic cells from a keyboard or guitar fill out the middle range; sustained bass tones teem over and threaten to overtake the mix; smudged aerial drones cloud the atmosphere.

Penciled in between engagements in Reznor and Ross’s already-overrun daybooks was enough spare time to finish a long-rumored project, one that they were still keeping mum about when SPIN spoke to them over the phone a week and a half ago: the upcoming Nine Inch Nails EP, Not the Actual Events, which was announced last week. In a press release, Reznor was willing to fill the picture out a bit more: “It’s an unfriendly, fairly impenetrable record that we needed to make.”

Between this, developing an expanded “2017 Definitive Edition” of 1999’s epic, famously impenetrable double album The Fragile (featuring 37 resurrected outtakes), and mounting vinyl reissues of formative NIN classics like 1992’s Broken EP and 1994’s The Downward Spiral, it’s remarkable that Reznor and Ross weathered the past year without missing deadlines or driving each other crazy. On a break from finishing the Patriots Day soundtrack album, they opened up to SPIN about conquering the unique challenges posed by their latest scoring projects, and channeling optimism into music during a devastating year.

How was scoring Before the Flood different than the work that you’ve done with David Fincher, both in terms of inspiration and process? Trent Reznor: Atticus had met Fisher [Stevens], who was already in the process of editing Before the Flood. The agenda was to get it out before the election to call some attention to climate change, which mysteriously had not come up, and was not going to come up, in any of the presidential debates. We knew we couldn’t turn it down. There was so much music that needed to be done in such a short timeframe. From a pragmatic point of view, we thought, “Let’s lighten the workload and see and invite some people who we’d love to work with.” Mogwai and Gustavo [Santaolalla] came up immediately. We reached out and it was a pretty good tagline: “There’s not much money involved, but it’s a good cause.” Initially the idea was going to be a quarter of the film would be the Mogwai score, then you get to the Gustavo section and then you get to our section. But as the film became more fluid and watchable, our fear was that it started to sound like a mixtape, where we just license music from different artists. For each film, you try to create a whole world sonically, having a sense of identity through instruments used, or recording techniques. Is it big Star Wars themes? Is it subtle mood enhancement? Or is it something you may not notice? So we were very open with Mogwai and Gustavo: “We’re going to send you whatever state whatever piece we’re working on is in. And if there’s anything in there that’s worth a shit–melody, chord change, sound, anything–feel free to do anything you want with it, turn it upside down, play on top of our track, re-record, take it on an 180 degree turn, or ignore it completely.” No one had any ego.

The film tries to instill hope for the future of the planet, but there are plenty of sections where it’s hard not to feel anything but despair, and a sense of inevitability. How did the “message”-based nature of the film affect your approach to scoring? Atticus Ross: It was important that it … not be entirely a message of despair. I think what did come out is very cohesive. Like Trent said, it is one of those things: It’s terrifying subject matter, but it was really good fun to work on.

Reznor: Fisher would re-iterate: At the end of the day, we want to alarm people, but leave the theater feeling like there’s a thread of hope there. When I watch an episode of Vice, I think, “What’s the point, man? The world is shit, and everybody in it dies—why continue?” Left to my own devices, in the face of the climate change deniers, the madness and the greed-based decision-making, and propaganda that’s been floating around, it’s hard not to become pessimistic. I think my instincts would be, “Let’s turn this into a Coil album, with gut-churning repulsiveness to show how ugly human beings are.” But Fisher was very adamant about keeping to what the message should be: one of optimism. I think that’s what’s kind of fun about taking on film projects coming from the background that we both have. In Nine Inch Nails, I’m writing the script. It can be about despair—in fact, it can be all about despair, and levels of depravity and desperation. In this case, I’m kind of forced to get out of what might feel more natural and comfortable.

With Patriots Day, what were the particular challenges with addressing such weighty and still relatively fresh source material? What appealed to you most about the project? Ross: I think that the goal, as it has been in the past, is, “Does it serve [the] picture?” It served this story, and in a particularly honest way, because of the nature of it. But there’s 140 minutes of music, and it was a challenge, on a thematic basis, as well as on a practical level. Reznor: I think in a brief nutshell, we were intrigued by the idea of doing it because it felt like such a different type of film. With an unknown quantity—the director [Berg], we didn’t know him personally. With Fincher, he’s a friend–a confidant. With the aspiration of trying new things and being put in potentially uncomfortable situations, the idea of an experiential film like [Berg] makes—and the million ways that it could go wrong against the backdrop of current event re-creation—the first and most important thing was to get a sense, from him, what his intentions were: that it was going to be respectful and tasteful, not a gung-ho-America, kill-them-all film. We quickly put those fears to rest. Then it was, for us, the challenge of working in a Hollywood kind of environment, and not making a Hollywood film soundtrack: not following the musical tropes that many seem to fall into, like the drums-of-war kind of mechanisms that you hear in countless other films. I think the movie turned out better than we even thought it might. There’s more music in it than I thought there needed to be, quite personally. The omnipresence of it, and the role of it in terms of carrying certain themes, makes me a little uncomfortable … I’m just being honest with you. That’s the catch about saying you want to be in an uncomfortable situation. It’s easy to say it, and then you actually realize, “Hey, I’m in an uncomfortable situation, and I don’t like it. It’s not comfortable.” We did manage to wander into that territory … again, it’s a process. I am pleased with the results of it.