“And then camouflaged it by coming to us and asking if the girl could come here?”

“Yes.”

“But Partridge never went out that afternoon.”

“We don’t know that. We were out ourselves, remember.”

“Yes, that’s true. It’s possible, I suppose.” Joanna turned it over in her mind. “But I don’t think so, all the same. I don’t think Partridge has the mentality to cover her tracks over the letters. To wipe off fingerprints, and all that. It isn’t only cunning you want—it’s knowledge. I don’t think she’s got that. I suppose—” Joanna hesitated, then said slowly, “they are sure it is a woman, aren’t they?”

“You don’t think it’s a man?” I exclaimed incredulously.

“Not—not an ordinary man—but a certain kind of man. I’m thinking, really, of Mr. Pye.”

“So Pye is your selection?”

“Don’t you feel yourself that he’s a possibility? He’s the sort of person who might be lonely—and unhappy—and spiteful. Everyone, you see, rather laughs at him. Can’t you see him secretly hating all the normal happy people, and taking a queer perverse artistic pleasure in what he was doing?”

“Graves said a middle-aged spinster.”

“Mr. Pye,” said Joanna, “is a middle-aged spinster.”

“A misfit,” I said slowly.

“Very much so. He’s rich, but money doesn’t help. And I do feel he might be unbalanced. He is, really, rather a frightening little man.”

“He got a letter himself, remember.”

“We don’t know that,” Joanna pointed out. “We only thought so. And anyway, he might have been putting on an act.”

“For our benefit?”

“Yes. He’s clever enough to think of that—and not to overdo it.”

“He must be a first-class actor.”

“But of course, Jerry, whoever is doing this must be a first-class actor. That’s partly where the pleasure comes in.”

“For God’s sake, Joanna, don’t speak so understandingly! You make me feel that you—that you understand the mentality.”

“I think I do. I can—just—get into the mood. If I weren’t Joanna Burton, if I weren’t young and reasonably attractive and able to have a good time, if I were—how shall I put it?—behind bars, watching other people enjoy life, would a black evil tide rise in me, making me want to hurt, to torture—even to destroy?”

“Joanna!” I took her by the shoulders and shook her. She gave a little sigh and shiver, and smiled at me.

“I frightened you, didn’t I, Jerry? But I have a feeling that that’s the right way to solve this problem. You’ve got to be the person, knowing how they feel and what makes them act, and then—and then perhaps you’ll know what they’re going to do next.”