"Before you start," my employer said, "I have a couple of questions. What were you told about this investigation?"
"I was told that Mr. Prescott's son was missing, and I was given a photograph of him. I was given a letter to read, the one which asked for money."
"And what assumptions did you make?"
"I'm not sure–"
"You're a professional. I'm sure you made some assumptions, even if you didn't voice them. I need to know what they were, since they would have affected what you did and how you understood the things you saw."
He hesitated, but Mr. Prescott said, "Tell her."
He nodded. "I figured that this was not a kidnapping, that he was not being held against his will."
"Nobody would kidnap him and ask for such a small ransom."
He hesitated, and Mr. Prescott said, "Because I have money, and could easily pay much more than that."
"And," she said, "if I may be blunt, because kidnapping your son could be viewed as a very risky action, so that's a small payoff for a big risk."
The detective nodded, and it was clear that he agreed.
"Any other assumptions?" she asked him.
"Two main possibilities that I could see. The tenants in the building are all female, so it is possible that one of them is involved with him, and persuaded him to do it. The other is that someone is copying his handwriting and that he isn't involved at all."
"Three scenarios, actually, if I understand you," my employer said, filling her pipe. "One, Jerry and a girlfriend, in collusion. Two, the girlfriend, forging his handwriting, sends the letter without his knowledge. Three, no involvement by Jerry at all, simply somebody with a handwriting sample, somebody who knows he's missing. What do the experts say about the handwriting in the note?"