Corporate defense attorney Robert Bilott finds himself drawn into a legal battle against the chemical manufacturing giant DuPont after a farmer from his hometown contacts him about a series of unexplained animal deaths. The farmer, Wilbur Tennant, believes that chemical runoff from a nearby DuPont landfill is poisoning his cattle. Initially hesitant, Bilott visits the farm and observes the disheartening evidence firsthand. Troubled by what he sees, he decides to investigate further, despite his law firm's established ties with chemical companies. Bilott's relentless search for the truth leads him to uncover a disturbing pattern of deception and environmental contamination linked to one of DuPont's chemical products.

As Bilott digs deeper, he faces mounting resistance from his employer and personal risk, but he remains steadfast in his pursuit of justice for the affected community. His investigation reveals that DuPont has been aware of the harmful effects of their chemicals for decades yet chose to conceal this information. Faced with overwhelming odds and legal battles, Bilott's struggle to hold the corporation accountable not only strains his career but also takes a heavy toll on his personal life and health. Despite these challenges, he continues his relentless fight against corporate malfeasance, striving to bring the truth to light and seeking justice for those harmed by the pollution.