That is to say, Edward Smith might not even know that his subordinates had investigated Helen two years ago.
He shared all of his analyses with Helen Melendy, who, being a lawyer, was naturally adept at catching the crucial points in Harry Hall's words, and said:
"So, someone from the Smith Family investigated me behind Edward Smith's back?"
If they purely suspected she might be the daughter of the Smith Family, there was no need to keep an eye on her for two years.
They definitely wouldn't have kept it a secret from Edward Smith, the Head, to keep an eye on her.
This doesn't seem like an investigation, it feels more like they are afraid of her appearing in the Smith Family's sight.
If not for Adam Jones having someone investigate Johnson Fefferman and incidentally tracing it to the Smith Family, she probably wouldn't have any connection to them up to now.
Is it possible she really is the daughter of the Smith Family?
