Definition of Irony
An important instance of dramatic irony occurs in Chapter 9, when Poirot interrupts a conversation with Sheppard, Flora, and Major Blunt to reach into the pond after something shiny. He comes up with nothing; after Flora and Major Blunt leave, Sheppard laments that Poirot got his suit muddy for nothing:
“And all for nothing, too,” I said sympathetically. “I wonder what it was in the pond?”
“Would you like to see?” asked Poirot.
I stared at him. He nodded.
“My good friend,” he said gently and reproachfully, “Hercule Poirot does not run the risk of disarranging his costume without being sure of attaining his object. To do so would be ridiculous and absurd. I am never ridiculous.”
In Chapter 27, Dr. Sheppard at last admits that he is the killer and explains how and why he did it. Even as he takes responsibility, he notes the situational irony that many other people seemed to implicate themselves in some way over the course of the investigation:
Unlock with LitCharts A+I wish I could have known beforehand that Flora was going to say she’d seen her uncle alive at a quarter to ten. That puzzled me more than I can say. In fact, all through the case there have been things that puzzled me hopelessly. Everyone seems to have taken a hand.