"That's better," Wolfe said. "First, Mr. Cather. Knowledge of a man cannot alone exclude him as a murderer, but it can as a blackmailer. Murder can be merely a spasm, but not blackmail. Four of us who have known Mr. Cather well for years – the two men I sent for, and Mr. Goodwin and I – agree that it can't possibly be Mr. Cather who blackmailed you. Now, the blackmailer. That name, Milton Thales – pronouncing it as you did and as almost any American would. But if I pronounce it Tha-lez does it stir your memory?"
"Should it?"
"Yes."
He was frowning. "Tha-lez – why, yes. An early Greek… eclipse of the sun… geometry…"
Wolfe nodded. "That's enough. A renowned name in the history of mathematics. Tha-lez of Miletus. Milton Thales. Barry Fleming, Miss Kerr's brother-in-law, teaches mathematics at a high school. Miss Kerr told her sister your name, and she told her husband. So I have named the blackmailer."
"Tha-lez," Ballou said. "Thales. Miletus. Milton. By God, I believe you have. And Isabel – Miss Kerr told me she had told my name to no one. She lied. I wonder how many more."
"Probably none. Those two were special to her. I think we may assume that only five people know of your connection with Miss Kerr: Mr. Cather, Mr. and Mrs. Fleming, Mr. Goodwin, and I. And only three know you were blackmailed, besides the blackmailer: Mr. Goodwin, you, and I. The two men upstairs, out of hearing, know of the blackmail, but not of you. I call your attention to a detail. My objective is to get Mr. Cather released and not charged with homicide. It's likely that I could achieve it simply by telling the police about Mr. Fleming blackmailing you. At least that would divert them, but I don't intend or desire to do it. I owe you some consideration, since I learned of the blackmailing only through you. I'm obliged to you."
Ballou reached a hand to tap the package. "And there's this."
"Yours. I haven't accepted it. Nor shall I, until I have concluded with finality that you did not kill that woman. A blackmailer is not
"Right away. A day or two later."
"Was it ever mentioned again? By you or her?"