Start: Countess: You seem troubled. Poirot: I am getting more and more concerned. Countess: That another crime will occur? Poirot: No. That I will solve this one. (Poirot picks up one of the passports and reads the contents) Countess. What is your maiden name?

[... … …]

End: Countess: It’s the truth, I swear to God! But I’ll tell you this: If I had known who he was - that he was Bruno Cassetti - the man who stole two of the people I loved most in this world - I would have pushed the dagger through his chest myself, and believe me, no other wound would have been necessary!

For full extended scene, please refer to clips or the script edition cited here: Ken Ludwig, Murder on the Orient Express, Samuel French, 2017, pp. 74-76.