The Mystery of the Blue Train · Chapter
A New Theory explained
Poirot visits Van Aldin at his hotel and re-interviews the maid Ada Mason.
What happens
Poirot visits Van Aldin at his hotel and re-interviews the maid Ada Mason. He suggests that the man seen talking to Ruth Kettering at the Gare de Lyon might have been her husband Derek, not the Comte de la Roche. Poirot also reveals that the jewels he showed Van Aldin the previous day were a first-class imitation, not the real rubies.
Themes in this chapter
Deception and Appearances
Poirot reveals that the jewels shown to Van Aldin were imitations, and suggests that the man seen with Ruth may have been Derek, challenging initial assumptions.
Characters to notice
- Hercule Poirot
Presents his new theory to Van Aldin, re-interviews Ada Mason, and reveals the jewels were imitations.
- Rufus Van Aldin
Receives Poirot at his hotel; is thunderstruck by the suggestion that Derek might have been the man on the train and by the revelation about the jewels.
- Ada Mason
Re-interviewed by Poirot; admits the man in the train could have been Derek Kettering and identifies the cigarette case as one Ruth bought for Derek.
- Derek Kettering
Implied as a possible suspect; Poirot suggests he may have been the man talking to Ruth at the Gare de Lyon.
- Ruth Kettering
Referenced as the victim; the cigarette case she bought for Derek is discussed.
Key passages
“I never thought of it that way. The master is tall and dark, and just about that build. It was seeing the hat and coat that made me say it was a gentleman from outside. Yes, it might have been the master.”
Ada Mason admits that the man she saw talking to Ruth could have been Derek Kettering, not a stranger.
Mason revises her earlier testimony under Poirot's questioning.
“What I showed you, M. Van Aldin, was a first-class imitation, hardly to be distinguished except by an expert from the real ones.”
Poirot reveals that the rubies he displayed were clever fakes.
Poirot's disclosure undermines the case against the Comte de la Roche.