His manner was perfectly natural.

“Yes,” said Poirot thoughtfully, “that describes Mademoiselle Katherine very well. It is very English, that phrase there, and Mademoiselle Katherine, she also is very English.”

Derek remained perfectly still without answering.

“And yet she is sympathique , is it not so?”

“Yes,” said Derek; “there are not many like her.”

He spoke softly, almost as though to himself. Poirot nodded significantly. Then he leant towards the other and spoke in a different tone, a quiet, grave tone that was new to Derek Kettering.