For the fifth time, Director Tony Scott and Denzel Washington have teamed up for another action thriller. Strangely enough, Unstoppable marks the second straight Scott/Washington combo that deals with trains. In last year's Taking of Pelham 123, Washington played an official in the underground subway industry. This time around Denzel is a train conductor above ground working one of his last shifts, operating an engine with the new up-and-coming company hire (Star Trek's Chris Pine).
Due to an error by a train worker, a fully linked multi-car train is on the loose, operating at speeds of over 50 MPH with no one driving it. Washington and Pine just happened to be in the wrong place and the wrong time and decide to try to run down the out-of-control train to slow it down before it reaches a populated area. As the action unfolds, we end up with three main characters in this movie: Washington, Pine and the runaway train itself. Scott does a great job with establishing the train as an independent character.