Hercule Poirot and Raymond Boynton in “Unfinished Business”

Hercule Poirot

Did Lady Boynton harm you physically?

My mother had little recourse to violence. She was too smart for that. Instead, she just prized open the top of our skulls and raked her poisonous tongue through our brains. No place to hide, Poirot. Even in your own head. Ever. Carol, um ... Carol grew up petrified. Did her best to ingratiate herself, you know, to win approval, which she never got. Jinny just was terrified to the point of madness. Possibly beyond.

Hercule Poirot

Did you murder your mother, monsieur?

No. But only because I lacked the moral courage. She was a monster, Poirot. It was her pleasure, always, to watch us suffer.

Hercule Poirot

Why was she driven to be so cruel?

To punish us, I guess.

Hercule Poirot

For what offense?

For being someone else's kids.