The Plymouth Express Affair: A Dramatized AI Audiobook

The Plymouth Express is one of the early Poirot stories Agatha Christie wrote for The Sketch, where it ran in April 1923 as "The Mystery of the Plymouth Express." In January 1924 it crossed the Atlantic in The Blue Book Magazine as "The Plymouth Express Affair," the American text and title this production uses. It was collected in The Under Dog and Other Stories in the United States in 1951 and in Poirot's Early Cases in Britain in 1974. Its real afterlife, though, is a novel. A few years later Christie took the same plot (an American millionaire's daughter, a fortune in jewels, a count she should never have written to, a body on an express) and expanded it into The Mystery of the Blue Train in 1928, trading a December train out of Paddington for the night express to the Riviera. Listening to the story after the novel is listening to the blueprint.

The production is one continuous 29m 55s chapter between opening and end credits, and it opens the way the story does, without Poirot. Lieutenant Alec Simpson, R.N., steps into a first-class compartment at Newton Abbot, notices a smell of chloroform he remembers from hospital, and finds that his suitcase will not go under the opposite seat. The sound design does the scene-setting a narrator would otherwise have to describe: a crowded steam platform, the whistle as the train draws out, the rattle of the carriage at night, a thread of tension from the moment he notices the smell, and the shriek of the brakes when he pulls the communication cord, all inside the first two minutes.

Then Poirot says "Mon ami," and the story becomes Hastings's. He tells it in the first person, so the narrator in this production is Hastings's own voice, and his lines in dialogue are the same voice. There are six speaking parts: Hastings, Poirot, Ebenezer Halliday, "the steel king of America," Inspector Japp, the maid Jane Mason, and Simpson, who has exactly two lines before he finds the body. A short story keeps a small cast, and here that is the point: everyone who speaks is a client, a witness or a policeman, and a listener never needs a "said Poirot" to know who is talking. Poirot has more lines than the rest of the cast put together, Hastings's narration aside, and a scene from this production, "Poirot, en français," plays on the Midsummerr homepage. Our guides to how many character voices an audiobook needs and what an AI narrator tells listeners explain why a small cast like this one still benefits from separate voices.

The middle of the story is three interviews, and the score stays underneath them. At five minutes the platform gives way to the quiet of Halliday's rented library in Park Lane, with a somber cue under his first words about his daughter: the twelve-fourteen from Paddington, the change at Bristol, and about a hundred thousand dollars of jewels in a small blue morocco case. Poirot pauses the interview to straighten an inkstand. At eleven minutes Jane Mason comes in, under a quieter suspense line, to describe her mistress's white fox toque and electric-blue coat and the man in the compartment who kept his back to her. Poirot then declines the case until Halliday admits what he has been holding back, a letter from the Count de la Rochefour. Japp arrives with what Hastings calls "a sort of affectionate contempt" and leaves for Paddington, and Poirot rings the Ritz and goes home to make a tisane.

The score picks up pace at twenty-one minutes, when Japp comes back to report his day: the knife found beside the line between Weston and Taunton, the paper-boy at Weston who was tipped half a crown, and a magazine with a girl in blue on the cover. A theme for the crooks comes in when one of the jewels turns up at a pawnbroker's, in the hands of a thief called Red Narky. The last five minutes belong to Poirot, and we leave them to him, except to say that the score moves from the edge of a reveal to an unmasking and then brings back the theme of the express itself. For how a mystery is directed and mixed so that the clues stay audible, see the mystery and detective production guide.

At thirty minutes it is one of the shortest productions in our catalogue and easy to finish in one sitting, which makes it a good first listen for anyone wondering whether their own book needs a full cast. It is one of the Agatha Christie productions in our free catalogue. Its natural companion is The Mystery of the Blue Train, the novel it became; The Murder on the Links and The Big Four are the Hastings-narrated novels from the same years.

The production runs 30 minutes and contains the whole story, unabridged and in order, from Simpson's suitcase to Poirot's last word, with opening and end credits. It is free to listen to.

The story was first published in 1923 and is in the public domain in the United States. Agatha Christie died in 1976, so it is still under copyright in the United Kingdom and the European Economic Area. This production is available to listen in the United States.

• Format: Full-cast dramatized audiobook
• Chapters: 3 (the complete story, plus opening and end credits)
• Runtime: 30 min
• Cast: Hastings narrating in character, Hercule Poirot, Inspector Japp, and six speaking parts in all
• Production: AI character voices, original music, and sound effects
• Price: Free to listen

Is this audiobook AI-narrated?

Yes. Every voice in The Plymouth Express Affair is AI-generated and produced by Midsummerr, with an original score and sound design. AI narration is disclosed as such on retail platforms that require it.

How long is the audiobook?

About 30 minutes: the complete story in one 29m 55s chapter, plus opening and end credits.

Who narrates it?

After a short opening scene on the train, the story is told in the first person by Captain Arthur Hastings, so the narrator in this production is Hastings's own voice, and his lines in dialogue are the same voice. Every other character, Poirot included, is a separate cast voice.

Is this the story behind The Mystery of the Blue Train?

Yes. Christie expanded The Plymouth Express into the novel The Mystery of the Blue Train, published in 1928, keeping the core of the plot and changing the names, the setting and much of the detail.

Why can't I listen in my country?

The story was first published in 1923 and is in the US public domain, but copyright in the United Kingdom and the European Economic Area runs for seventy years after the author's death, and Agatha Christie died in 1976. The production is available to listen in the United States.

Where can I listen?

Listen free at midsummerr.com/listen/plymouth-express-affair-agatha-christie.