If you were to wander accidentally into the opening scenes of Dark Waters, you might dismiss it as a generic horror. A gaggle of teenagers jump the fence to swim in an inky lake, spied by some underwater predator. A television monitor displays grainy VHS footage of a tumour spilling out of a cow’s skull. A beleaguered Mark Ruffalo sits alone in a dark office, entombed in paper, trying to find the evidence to nail the perpetrator. Without context, there’s nothing remarkable about these scenes. But stay to the end and you’ll learn that what makes Todd Haynes’ 2019 film so disturbing is not only that it’s all true, but that each of us is far more intimate with its antagonist than we’d imagine. That antagonist is actually a chemical, PFOA, belonging to a notorious class of highly toxic and carcinogenic substances known as PFAS (“forever chemicals”). Until recently, the primary commercial producer of PFOA was the company DuPont, which – among other things – used it to produce the popular non-stick Teflon pans that have dominated kitchens from the 50s to now. We owe our awareness of the existence of PFOA largely to a lawyer named Rob Bilott, a corporate defence attorney who spent most of his career defending chemical companies; and to the West Virginia farmer Wilbur Tennant (an acquaintance of Bilott’s grandmother), who called to say a nearby DuPont landfill was poisoning his cows. Bilott’s ensuing decades-long battle with the petrochemical behemoth was chronicled in a 2016 New York Times magazine feature which became the basis of Dark Waters. Many auteurs have one film in their repertoire that sticks out awkwardly and the uncharacteristically realist Dark Waters – which follows the Times feature almost beat by beat – might appear so for Haynes, otherwise known for his wicked provocations and luxurious melodramas. In some ways, though, Haynes has been making films about contamination and toxicity for his whole career. The clearest parallel is 1995’s Safe, in which Julianne Moore plays a housewife who suffers from a mysterious intolerance to common household chemicals. But less obvious entries – recent critical hit May December, or his beloved queer romance Carol – also grapple with how to live amid the world’s systemic toxicity, whether it’s a substance, a political system or a cultural norm. Sign up for the fun stuff with our rundown of must-reads, pop culture and tips for the weekend, every Saturday morning The melancholic Ruffalo is a perfect choice for lawyer Bilott: hunched, recalcitrant and increasingly borne down by gravity over the course of the film. More than once we find him softly weeping into the shoulder of his wife (Anne Hathaway), who – largely left alone to raise the kids – suffers a tug-of-war between pride and frustration. The real couple appear as cameos in the film too, alongside the real Bucky Bailey, one of many children of workers on the Teflon line who suffered from prenatal exposure to PFOA. Such details speak to the fact that unlike many recent releases (looking at you, The Iron Claw), Dark Waters has a deep commitment to the ethics of telling a true story. It’s a subject upon which Haynes has reflected at length: in May December, an actor meets the tabloid-famous housewife she is meant to portray. Where another might have taken more liberties with Dark Waters’ courtroom scenes, Haynes foregrounds their futility. DuPont is not an enemy one can defeat with a single blow; in fact, it is unclear if defeat is possible at all. As an exasperated Bilott says towards the end of the film: “They want to show the world that there’s no use fighting.” The thing about toxicity is that unlike a monster or a serial killer, one rarely knows when it has struck. As Bilott finds evidence of PFOA first in Wilbur’s farm, then in the town’s drinking water, and finally in the homes of nearly all Americans, that threat draws ever closer. Arriving home in the middle of the night, Bilott begins tearing up the linoleum flooring, pulling the pans out of the cupboard. It’s too late for him, of course – it’s too late, even, for his unborn baby. By the end of the film it hardly comes as a surprise to us that PFOA exists in the bloodstream of 99% of people on Earth, as well as in nearly every other living creature. DuPont discontinued the use of PFOA in 2015 but most PFAS are still unregulated. You’ll find them in your cosmetics, food packaging and furniture. Like most modern horror stories, the calls are coming from inside the house.