So he remained puzzled how to act, how to deal with this unexpected situation.
It was her ladyship who was the first to break the silence.

She had been considering Mr.Caryll through narrowing eyes, the corners of her mouth drawn down.

She had caught the name of Maligny when it was uttered, and out of the knowledge which happened to be hers--though Mr.Caryll was ignorant of this--it set her thinking.
"I do not believe that you are the son of Mademoiselle de Maligny," she said at last.

"I never heard that my lord had a son; I cannot believe there was so much between them." Mr.Caryll stared, startled out of his habitual calm.

Rotherby turned to her with an exclamation of surprise.