Charlie wasn't sure why his mother had reached that conclusion, but he agreed with Vera's point of view.
Some people could deduce entire revelations from a handful of clues, or through the basic but unwritten underlying laws and logic. The best example of the former was Merlin. While he used to think Vera was the best example of the latter, he now thought his mother must be on par with Vera as well.
For Vera's part, she didn't need to wait to check with Ashley—the image in her mind couldn't b