Horror movies condition us be cautious of our surroundings—to flinch at the sound of a creaking floorboard or a sudden chill in the air. But the biggest scares in life are the ones that come from things we think are completely safe. In Dark Waters, the evil lies in frying pans. But as it goes, that innocuous household staple is a window into a greater terror.

The thriller, which was directed by Todd Haynes and hits theaters this week, draws from a 2016 New York Times article by Nathaniel Rich to tell the real-life story of corporate lawyer and environmental activist Rob Bilott (played by Mark Ruffalo), who won a $670 million cash settlement for thousands of people affected by exposure to harmful chemicals at the hands of the DuPont chemical company. Bilott, a partner at a Cincinnati law firm, spent the beginning of his career fighting on behalf of large chemical corporations, but in 1998, he decided to take on one of the biggest ones in the world.

After receiving a desperate call from a farmer named Wilbur Tennant (Bill Camp), an acquaintance of his grandmother who’d captured footage of his cows being gruesomely ravaged by some unknown disease, he discovered that DuPont had been exposing plant workers and residents of Parkersburg, West Virginia, and other neighboring towns with hazardous substances found in Teflon, leading to high instances of chronic illness, birth defects, and death.

"I saw the footage of the cows, and that's the original footage [that you see in the movie],” Ruffalo told VICE on a cold afternoon in November. “That's Wilbur Tennant's footage. I saw that, and I was like, 'This is a horror story. A real-life horror story.'' Clad in a suit and tie he seemed uncomfortable wearing, the actor and longtime environmental activist spoke with the fervor and wear of someone who's been in the fight for a long time. So stepping in to play Bilott, a man who has dedicated decades to get justice for the many affected by DuPont's gross malfeasance, seemed only natural. "I was floored by the story and just the enormity of this cover-up, how many people must've been involved in it,” he said. “I thought it was also a microcosm of a bigger systemic issue in the United States."

In 1938, Roy J. Plunkett, a chemist employed by DuPont, accidentally invented a seemingly miraculous polymer they named polytetrafluoroethylene, then later, simply "Teflon." By the 1950s, teflon-coated non-stick frying pans were being sold widely as a brand new secret weapon for housewives: here's a wonder pan that will keep food from burning and sticking while cooking! Today, you can walk into any Bed, Bath, & Beyond or TJ Maxx and buy Teflon-coated pots and pans at a low, low price. But that's not all! Teflon is also used in a variety of products, including waterproof clothing, rugs, pizza boxes, furniture, dental floss, hair straighteners, and microwave popcorn bags, as well as in firefighting equipment. Here's the thing, though: Teflon contains perfluorooctanoic acid (PFOA), otherwise known as C8, part of a larger cluster of "forever" chemicals called PFAS or PFOAs that never break down in the environment and build up in humans and animals, causing irreparable damage.

And yet, DuPont is still the only manufacturer of Teflon, now with a slightly less hazardous chemical compound called GenX, which has been questioned for its own dangerous properties. Even with the bad press around Teflon and PFAS, DuPont is still thriving. In 2018 alone, the company brought in a total revenue of $22.7 billion. Countless companies globally sell Teflon products.

"When you see what these people are capable of, how willfully they knew exactly what they were doing and kept doing it because they were making so much money, it makes you mad," Haynes said.

The director, who spent time in Parkersburg and Cincinnati along with Ruffalo and co-screenwriter Mario Correa in 2017 and 2018, marvels at the sheer magnitude of DuPont's actions, and what it means on a larger level. "The fact that we're also contaminated by this water—it's in all of us. It kind of links us in a way," Haynes said. "Not that we ever were asked for permission to have our bloodstreams be forever changed for the ease of non-stick cookware. But [the situation is] a metaphor for the way the system invades us, and that we have to be diligent and knowledgeable and stand up and pick our battles. If we keep doing that, there will be change."

It's impossible not to feel horrified and infuriated in watching Dark Waters, or feel the weight of responsibility on Bilott's shoulders to be the David taking on a billion-pound Goliath. In one scene, Bilott comes face-to-face with Bucky Bailey, the son of former DuPont employee Sue Bailey. During an earlier contentious meeting with DuPont, Bilott holds up a photo of Bucky as a newborn, his little face made up of a serrated eyelid and only half a nose. Later, at a gas station, a male voice asks Bilott for the score of a game, and he turns to find that same face aged 30-odd years, leaving him shaken. It's even more unsettling when you realize the real Bucky Bailey plays himself in that scene.

"It's such a long journey for [Bilott], and it just took its toll on him, financially, socially, with his career, his family, his community. It was a very grueling slog," said Ruffalo. "You're living in that every single day. Those scenes where I'm sitting there in despair, I didn't have to act very much."

Ruffalo continued: "[Activism is] so hard and thankless and fucking despairing," he said. "Part of the reason I wanted to do this was because I've done so much activism." Ruffalo started The Solutions Project in 2011 to fund and provide resources to small groups and organizations working to "transition their communities to 100 percent renewable energy," particularly ones lead by women and people of color. He's also had a history of choosing films that speak to social injustice, including 2015's Spotlight. Ruffalo believes film is a powerful tool for social change, shocking people into action in a way activism may not be able to. With Dark Waters, he's continuing on this path: The film’s launch coincides with his new Fight Forever Chemicals campaign with activist media company Participant, focused on raising awareness of the damage that forever chemicals cause and pushing government agencies like the EPA to regulate them.

"This is the sickness of our culture right now, where democracy is in service of capitalism instead of the other way around,” Ruffalo said. “If you measure a country's health and their well-being on the GDP alone, then you're gonna have a lot of sick people running around."

Ruffalo has already spoken at the U.S. Capitol and testified before the House Oversight and Reform Subcommittee on the Environment, urging the EPA to take stronger steps in regulating forever chemicals. Ruffalo blames corporate greed and interests for the lack of movement in safeguarding the public from PFAS.