Dr. Lewis Shaler and his son Max are traveling by train to London. Lewis will leave Max to attend the funeral for victims of a great accident at the hospital where he works. When Max accidentally spills coffee on Sarah Barwell, Lewis offers to pay for the cleaning, and soon they start a talking. When the train stops, Lewis sees a man on the track apparently fixing the brakes. When the trains moves, he sees another man crawling on the tracks. Lewis seeks out the train conductor and finds he's missing. When the train bypasses a stop, he tries to contact the driver. After talking with the few passengers onboard, they realise the train has no brake and the driver's suicidal.