A murder at a rail yard leads us to investigate a possible terrorist plot developing using trains as delivery vehicles for bombs. A former employee who tried to be a whistleblower hijacks a train to reveal to the world that the train company is sending dangerous chemicals through populated areas. We discover the whistleblower is being used by a man who planted a bomb on the tracks and plans to let the train explode in a densely populated area. While the whistleblower tries to stop the sabotaged train, Sam finds the bomb and disarms it just in time.
