"What caused your mother's illness ?" he asked, abruptly.
The question troubled her.

It struck her with a pang of self-reproach that she had always been indifferent to her mother's illness, regarding it as more or less imaginary.

"It was mental rather than physical, I think," she answered.

"I never knew what brought it about." Again he looked at her with that odd, inquisitive expression.

"She never got over it ?" he asked.
"Oh, there were times," answered Joan, "when she was more like her old self again.