Poirot said: ‘You are content for the murderer to escape unpunished?’
‘There are probably several undiscovered murderers at large in the world.’
‘That, I grant you.’
‘Does one more matter, then?’
Poirot said: ‘And what about the other members of the family? The innocent?’
She stared. ‘What about them?’
‘Do you realize that if it turns out as you hope, no one will ever know. The shadow will remain on all alike…’
I completely forgot this reference to Ordeal by Innocence was in here.