During an unfortunately ominous conversation about the frequency of undetected acts of poisoning in Chapter 1, Emily Inglethorp uses a simile to express her displeasure with the direction of the group’s subject matter, thereby foreshadowing her imminent death:
Why, Mary, what a gruesome conversation!” cried Mrs. Inglethorp. “It makes me feel as if a goose were walking over my grave. Oh, there’s Cynthia!
Emily’s declaration that Mary and Hastings’s casual discussion of poison and rampant, unpunished murder is deeply prescient. The vivid specificity of her language contributes to the foreshadowing effect of the passage above. Her claim that such lighthearted musings about murder and poison make her feel like a "goose is walking over her grave" signals that she will not last long in this narrative. This simile is functionally equivalent to the phrase "a chill went down my spine." Thus, it conveys Mrs. Inglethorp’s psychological fear and physiological discomfort at the possibility of being poisoned and the distinct threat of that crime’s potential to go undiscovered. This conversation is therefore also an ironic bit of foreshadowing, as Emily meets her own demise by way of poisoning and the culprits responsible for her death are present to hear her express the depth of her negative feelings towards this particular kind of death.
In Chapter 10, Poirot is refreshed by his latest discovery in the case regarding the letter Lawrence Cavendish receives from the costume company, and he uses the following simile to express his excitement:
See you, one should not ask for outside proof—no, reason should be enough. But the flesh is weak, it is consolation to find that one is on the right track. Ah, my friend, I am like a giant refreshed. I run! I leap!
Poirot’s language in the passage above is one of his most vibrant and expressive moments in the novel. Invigorated by his newest clue, he rushes outside, declaring that he feels "like a giant refreshed." This simile conveys an almost childish enjoyment of casework, which is sweetened by the fact that his devotion to his methodology is beginning to pay off with quantifiable results.
Importantly, the closer Poirot gets to solving the crime, the more he lets loose on his strict control over his expressions and emotions. This moment allows Poirot’s personality to shine through more than it has earlier in the novel. This stands in contrast to Hastings himself, who wears his heart and thoughts on his sleeve and often allows his emotions to jump the proverbial gun over logical reasoning. Poirot’s excitement at the progress of the case endears him further to both the reader and to Hastings, adding more personal stakes for the reader to follow along with the detective’s journey of crime-solving antics.