Set in Pennsylvania coal country, the film centers on Joe Radek, a miner of Slavic background. After a heated argument with his girlfriend Anna Novak, he drinks and becomes embroiled in a volatile union meeting, where his presence helps drive a split between radical and moderate factions. The radicals walk out and strike, while the moderates, led by Radek's best friend Mike Shemanski, stay at work and try to keep the mine’s operation running. The company responds by hiring a private police force cobbled together by a Pinkerton‑type detective agency, turning the conflict into a battlefield of labor and coercion.
One night, three drunken company cops attempt to rape Shemanski’s daughter, and the two friends rally to defend her honor. The confrontation turns tragic when Shemanski is killed by McGee, and Radek is left injured and hospitalized. While he recovers, the strike fizzles without concessions, and the murder goes unpunished, fueling Radek’s anger and sense of injustice.
Driven by a sense of duty and wounded pride, Radek bands together dynamite and provisions and resolves to wage his own underground protest. He hides in the mine during the day and strikes at night, blowing up company property as a dramatic statement against the corporate powers that crushed the union’s chances. His bold, dangerous campaign draws national attention once the media begins reporting on the action, turning a regional labor dispute into a national talking point.
As the chase intensifies, corrupt company cops close in, and Radek fights back with the tools at hand. In a tense, claustrophobic sequence, he battles through the mine tunnels and, in a climactic moment, inadvertently seals himself with McGee’s killer in a secret passage. When the dust settles, Radek emerges with a subdued company policeman in tow, delivering him to those who will seek justice and public accountability for the violence that erupted underground.
In the aftermath, Radek’s stand publicly vindicates him, shifting sympathy toward the miners and helping to push for a more favorable union contract for his fellow workers. The victory is not just contractual but personal: Radek reconciles with his girlfriend Anna Novak, underscoring a hard‑won balance between romance, rebellion, and responsibility in a town shaped by the weight of the mine.
