In the heart of Pennsylvania, a half-mile-long freight train carrying hazardous chemicals becomes an unstoppable force after it starts moving with no one aboard due to an engineer's error. The train, nicknamed "the beast," threatens to wreak havoc on densely populated areas along its path, including a curve in a populated town that could result in a catastrophic derailment. Local and state authorities scramble to figure out a way to stop the behemoth, but their initial attempts prove futile, setting the stage for a dire situation.

Amidst the chaos, a veteran engineer and a young conductor, both working on a separate locomotive, become aware of the impending disaster. Despite having their personal struggles and differences, they decide to take matters into their own hands in an audacious attempt to avert the disaster. The duo embarks on a high-stakes chase to catch up with the runaway train, facing numerous challenges along the way. Their mission becomes a thrilling and perilous journey, showcasing not only their bravery and determination but also highlighting the potential for unexpected heroism in the face of overwhelming odds.