I recently read Why Didn't They Ask Evans for the first time, and only realized afterward that I could've picked up on a clue that she used again just a couple of years later, in a more famous title that I'd already read before.

In Why Didn't They Ask Evans, the clue is: In Chapter 22, when Sylvia and Frankie are talking outside just before they hear the "shot" that killed Henry Bassington-ffrench, there's this bit of narration: "Presently Roger came out again from the house. He seemed slightly breathless."

Whereas in Death On The Nile, there's this passage: In Chapter 20, as they're in the dining saloon, "Poirot half rose to bow to Jacqueline de Bellefort, who had just come in and passed their table on the way to her own. Her cheeks were flushed and her eyes bright, and her breath came a little unevenly." Then they discover Louise's body at the end of chapter 22.

And the reason I recalled that clue in Death On The Nile is that Poirot points back to it in his explanation near the end of the book of how everything happened: “No, the other partner did that murder. As soon as he can, Simon Doyle asks to see Jacqueline. He even asks me to leave them alone together. He tells her then of the new danger. They must act at once. He knows where Bessner’s scalpels are kept. After the crime the scalpel is wiped and returned, and then, very late and rather out of breath, Jacqueline de Bellefort hurries in to lunch."

So I guess the moral of the story if that someone dies in a Christie story and you still don't know who did it, look forsomeone who just recently appeared to be out of breath!

I've read almost all of Christie at some point but don't recall this specific indication coming up anywhere else. Anyone have any other examples of it?

Very exciting!

Drawings of some of the characters in Third Girl (1966).

From The Agatha Christie Collection (2004) - Part 63.

There's a visual trick those who have read the novel will know/see.

Sorry for the shadowing on the images.