The film is set on a commuter train. Macaulay (Liam Neeson), a businessman who has been commuting to get off work by train for ten years, encounters a "mysterious passenger" Joanna (Vera Farmiga) who takes the initiative to strike up a conversation. Joanna offers Macaulay a very tempting task - to find a passenger on the train and get a huge amount of cash in return. But in the process of searching, Macaulay gradually finds himself involved in a deadly and dangerous situation. Can he successfully escape from this "terror train", and what kind of shocking conspiracy is hidden behind it? As the train continues to accelerate, the truth is revealed one by one...