In the bustling heart of New York City, a subway train, Pelham 123, is hijacked by a menacing group of criminals led by a man codenamed "Ryder." The hijackers take the passengers hostage and make a precise demand: a ransom of $10 million dollars to be delivered within an hour. Failure to comply will result in the death of hostages, executed on a strict timetable. The situation escalates as the entire city's attention turns towards this audacious act of urban terrorism, gripping the citizens with fear and anticipation. The city's officials scramble, under the immense pressure of the ticking clock and the eyes of the public, to formulate a response to the unprecedented challenge they face.

The task of negotiating and dealing with the hijackers falls on the shoulders of Walter Garber, a New York City subway dispatcher with a rich knowledge of the subway system but no experience in crisis management. As he is thrust into the center of this maelitic ordeal, Garber must use his wit and resourcefulness to outsmart the hijackers and save the hostages. His conversational exchanges with Ryder reveal not only the complexities of their personalities but also hint at the hijacker's motivations. As the deadline looms closer, the tension between the two men intensifies, setting the stage for a confrontation that tests the limits of bravery, negotiation, and sacrifice. The city watches on, waiting to see how this perilous situation will unfold, hoping for a peaceful resolution amidst the chaos.