In 1876, deep within a Pennsylvania coalmine, the harsh realities of life for miners are starkly portrayed. It is a time when coal is painstakingly extracted by hand and transported on rudimentary rails with the help of ponies. The miners face grim conditions marked by dirt, cramped spaces, and poor health. They rely on primitive naked flames for light, although it is noteworthy that historically, such flames were enclosed since the 1820s due to the introduction of the Davy lamp. As the workers are seen preparing charges, the tension escalates and ultimately culminates in a catastrophe: an explosion devastates the mine, marking the beginning of a perilous investigation.
Enter Detective James McParlan, portrayed by Richard Harris, who is dispatched by the Pinkerton National Detective Agency to uncover the truth behind the disastrous event. Arriving on a late evening train, McParlan enters a local bar, where he orders a beer, hoping to glean information about the mines. Seated at a card table with Anthony Zerbe as Dougherty and Art Lund as Frazier, he proclaims his search for work in the mines. However, their skepticism is fueled by their observation that his hands are unblemished by labor, leading to accusations of cheating that erupt into a brawl. The police captain, Frank Finlay, intervenes, arresting McParlan, but this is merely a ruse; the police are aware of his undercover intentions.
Explaining the looming threat of the Molly Maguires, a secretive society named after a historical gang from Ireland, Captain Davies reveals the urgent need for an inside man. Cleverly assuming the alias "McKenna," McParlan secures lodging with Mary Raines, portrayed by Samantha Eggar, before heading to the pit for work. His first day proves grueling, further compounded by paltry wages. After diligently working throughout the week, he finds himself disheartened to receive mere cents after numerous deductions. Despite this, he finds a moment of solace in a local bar where he catches the eye of Sean Connery as Kehoe, who begins to watch him closely.
The narrative progresses as a priest admonishes the recent actions of the Molly Maguires, hinting at a brewing storm as McParlan, now fully immersing himself in the lifestyle of a miner, struggles to maintain his cover. A staged accident orchestrated by Kehoe brings McParlan deeper into the trust of the miners. McParlan fabricates a confession of being a wanted criminal, further entwining himself in the clandestine underpinnings of the group. The tension escalates with violent encounters, arrests, and revelations that blur lines between right and wrong.
Amid the chaos, the relationship between McParlan and Mary blossoms, filled with morality discussions during idyllic picnics. However, the backdrop of violence looms large as brutal retribution occurs, marking a tragic turning point during the funeral of Frazier and his wife, victims of police brutality. As the investigation unfolds, the stakes become alarmingly higher. McParlan's covert role as a spy reveals an intricate web of deceit that endangers not just him, but everyone around him, including Mary, who is left heartbroken at the betrayal when the truth of his identity comes to light.
As tensions reach a boiling point, McParlan's duality as a lover and a traitor becomes evident. He finds himself face-to-face with Kehoe in a climactic moment in the death cell, where they share a poignant conversation about redemption and betrayal. In a desperate moment, Kehoe's fury showcases the deep-seated feelings of betrayal while McParlan defiantly suggests that if hell is his destination for his treachery, he will see Kehoe there. This powerful exchange encapsulates the essence of humanity caught in the turmoil of morality, loyalty, and the struggle for survival amidst the harsh realities of life in the mines.
