At Felixstowe, workers are carrying bags of oats from cargo ships that have come into port. One of them rips open a bag with a knife, but is stopped by his foreman before he can investigate its contents.
Meanwhile, a train hits a man on the platform as it passes Hellbridge station. A few hours later, the police arrive and investigate the scene. The Inspector doesn't believe it was an accident, and asks what time the train went past. He is told that it was 7 o'clock - the time when the 'ghost train' is reputed to haunt the tracks...
Later, passengers at another station board a train to Hellbridge, where they will be able to pick up a connection to London. Miss Ophelia Bourne arrives with her pet parrot, and is joined by a young couple, Peggy and Charles Murdock, and the married Elsie and Richard Winthrop, who are always arguing and on the verge of divorce.
The train is also boarded by Teddy Deakin, travelling alone, who pulls the alarm cord when his hat falls out of the window. This delay results in everyone missing the last train to London, and resigning themselves to staying the night at Hellbridge station.
Inside the station waiting room, Deakin's sense of humour starts to grate on everyone, and Richard gets up to hit him. As he does, Deakin looks down the track and sees a light approaching the station. The stationmaster sees it and slams the door of the room shut. He explains his actions by saying that it is the light of the ghost train, and then begins to tell them the story.
Some years ago, a telegram arrived for Hellbridge's former stationmaster, Ted Holmes, saying that a special train service would be arriving in ten minutes. The stationmaster didn't have time to lower the bridge crossing a river on the way to the station, and the train plunged into the water. The ghost of the driver, Ben Issacs, now haunts the station, and the light from his lamp can be seen before the ghost train's arrival.
To calm their nerves, the group have some drinks and put on records, but their party is broken up by the arrival of a woman called Julia. She tells them that she has seen the ghost train, and implores them to protect her from two men who are after her.
The men arrive, and Deakin tries to cover up for Julia, but they find her hiding behind the door. They are about to take her away, when a telegram arrives - at the same time as the telegram did for Ted Holmes.
Deakin reads the telegram, which is identical to the message Holmes received. Julia looks out of the window and says that she can see Holmes. Deakin opens the door and finds the current stationmaster laying on the bridge controls, apparently dead.
The two men bring his body in and put it in a side room. While they do this, Deakin inspects the tracks, and uses the controls to change their direction. On his return to the station, he notices the stationmaster's 'body' get up, confirming his suspicions of foul play. Secretly, he hands a gun to Richard for their protection.
At the expected time, the 'ghost train' arrives, but because Deakin has changed the direction of the tracks it is forced to stop. The two men try to run, but Deakin draws a gun. The stationmaster comes out from the back room and grabs Deakin, but Richard draws his own gun.
The police arrive and arrest the people who were driving the 'ghost train'. Upon opening the bag of 'oats' the train was carrying, they discover that it is full of guns. Deakin explains that they were transporting guns from Hamburg. The conspirators are arrested and taken away by the police.
Richard and Elsie embrace, their marriage now saved, and they and the other passengers wait for the next train to London.
