Christie presents a satirical portrait of religious intolerance and moral harshness in the figure of Miss Emily Brent, a deeply religious and old-fashioned older woman who ruthlessly judges others for what she regards as sin:
In a non-smoking carriage Miss Emily Brent sat very upright as was her custom. She was sixty-five and she did not approve of lounging. Her father, a Colonel of the old school, had been particular about deportment. The present generation was shamelessly lax—in their carriage, and in every other way….
Enveloped in an aura of righteousness and unyielding principles, Miss Brent sat in her crowded third-class carriage and triumphed over its discomfort and its heat. Everyone made such a fuss over things nowadays! They wanted injections before they had teeth pulled—they took drugs if they couldn’t sleep.
In the scene in which she is introduced, Brent is presented in a satirical fashion that underscores both her strict adherence to antiquated rules of conduct and her strong sense of moral superiority. She regards, for example, younger people as “shamelessly lax” for using modern comforts such as anesthetics during dental surgery, suggesting that she believes there is virtue in experiencing pain. Christie’s narration emphasizes her feelings of “righteousness,” and later scenes in the novel will highlight the cruelty and hypocrisy of her “Puritan” interpretation of her faith.