"Doctor Gu said the paternity test is real," Zoey Parker came back and told them the result from Doctor Gu, which meant Ryan Parker was indeed the Noah Wilton of those years.
Then why had their mother been so sure that Ellie Wilton's son had died? What exactly happened in that fire years ago?
"If Doctor Gu says it's real, then it must be," they believed in Doctor Gu's words because he was a confidant of their mother. Moreover, Doctor Gu had loved their mother and had never married for her sake. He had served Hannah Browman before, and now he served the four of them.
Marcus Parker's decision to involve Doctor Gu in this matter was to ensure that the final result would convince all four of them.