I SAT WITH BETH in her expensive off-white living room, which looked like it had been decorated by the pound. Beth was in a black dress that proclaimed her mourning and showed off her body.

“I’m sorry for your loss,” I said.

“You told the police about me,” she said.

“I did.”

“That was mean,” she said.

“No, it wasn’t,” I said. “I’m your alibi. You would have told them you were with me, and I would have confirmed it, and the cops would have said, ‘How come you didn’t tell us about her?’ ”

“Why do I need an alibi?” she said.

“You’re the spouse of a murder victim.”

“And that automatically makes me a suspect?” she said.

“They have to eliminate you,” I said.

“I suppose,” she said.

“Any thoughts on who might have done it?”

“I should think the warning note I showed you would be a clue,” she said.

“Not much hard information,” I said. “Do you still have the envelope?”

“Envelope?”

“That it came in.”

“Oh, no,” Beth said. “I threw it away. There was no return address or anything.”

“Was it addressed in hand or typed or one of those little computer address stickers?”

“Hand,” she said.

“Remember where it was postmarked?”

“Boston, maybe,” she said. “I don’t know. I’m not used to threatening letters. I’m not a detective. I just threw the envelope away.”

“Sure,” I said. “Nice outfit you’re wearing.”

“Oh, this, well, it’s… I’m kind of in mourning. You think it’s okay?”

“Swell,” I said. “Are you his only heir?”

“There’s a couple of ex-wives,” she said. “No children. I’m the only one in the will.”

“Well,” I said. “There’s a plus.”

“It is a plus,” she said. “But there’s no need for you to be so snarky about it. My husband has just been murdered.”

“True,” I said.

“I mean, we had our problems, sure…”

“And now you don’t,” I said.

She was sitting on the ivory-colored couch. I was sitting on a straight-backed armchair across from her. She squared her shoulders and sat more upright.

“Do you suspect me?” she said.

“I remain open-minded,” I said.

“What a terrible thing to say. It’s disgusting that you could even think that.”

“Disgusting,” I said.

“Why do you even care?” she said. “Has someone hired you to work on this case?”

“No,” I said.

“Then why don’t you go off somewhere and be disgusting on someone else’s business.”

“I’ve been involved with this for a while,” I said. “It’s my line of work. I feel some obligation to see what I can do.”

“Well, don’t think you have any obligation to me,” Beth said. “I’d like it if I never saw you again.”

“You, too?” I said.

I SPENT THE WEEKEND at Susan’s place, where, after some early morning excitement, we usually sat in her kitchen and had a lingering Sunday brunch prepared mostly by me. This morning was a little different; we were having scrambled eggs prepared by Susan. It was one of her two specialties, the other being boiled water. I added a ragout of peppers, onions, and mushrooms to grace the plate, and we ate it with oatmeal toast. Pearl came from her spot on the living-room couch and joined us, alert for any spillage.

“I talked with Beth Jackson on Friday,” I said.

“Are you still suspicious of her?”

“Let me recount our discussion,” I said.

“I’m all ears,” Susan said.

“Actually,” I said. “Not all.”

She smiled, and I gave her, almost verbatim, my conversation with Beth.

“You like to show off that you can do that,” Susan said. “Don’t you.”

“Yes,” I said. “Is there anything bothersome about what you heard.”

“Your voice was sexually exciting?” Susan said.

“Besides that,” I said.

“In relation to the murder,” Susan said.

“Yes.”

Susan was silent, her mind running over the conversation. “Remember why she came to me the night of the murder,” I said.

“She wanted you to protect her,” Susan said. “And, at least peripherally, her husband.”

“Correct,” I said.

“And now”-Susan began to speak faster, trying to keep up with her mind-“when half the threat has been executed, she should be more desperate for protection.”

“Bingo,” I said.

“And she isn’t,” Susan said. “She doesn’t want to ever see you again.”

“Or words to that effect,” I said.

“Which would lead a trained observer,” Susan said, “to conclude that she no longer thought there was a threat.”

“It might,” I said. “Or she might have found me so disgusting that she preferred to look elsewhere for protection.”

“No,” Susan said. “Not if she’s in fear of her life. However disgusting she may have found you, you are also safety. She would have embraced you.”

“Who wouldn’t,” I said.

“I was speaking metaphorically,” Susan said.

“Oh,” I said.

“But we know she didn’t do it herself,” Susan said.

“I can vouch for that,” I said. “In fact, it seems too carefully done. She comes to me at five. At five-ten an anonymous caller reports a shooting, cops are there by five-thirty. Beth doesn’t leave my office until about six.”

“A lot of people could have made an anonymous call,” Susan said. “They saw it happen but didn’t want to be involved.”

“Nine-one-one records all call numbers. This one was from a disposable phone.”

“They can’t trace it?”

“Correct,” I said.

“So it could have been someone who just happened to use a disposable phone, or it could have been a deliberate way to avoid identification.”

“How many people you know that carry disposable phones?” I said.

“Nobody.”

“Guy also tried to disguise his voice. Belson said it’s a man speaking in a falsetto.”

“So it could have been the murderer,” Susan said.

“Could have been,” I said.

“But why would he call the police? Wouldn’t it be in his better interest not to?”

“One would think,” I said.

“Unless he wanted to establish that the murder took place while Beth was with you,” Susan said.

“Which means she was involved,” I said.

“Or Estelle,” Susan said.

“Or both,” I said.

“Why would Estelle be involved?”

“Why do people usually kill other people?” I said.

“Mostly over love or money,” Susan said.

“If Estelle’s involved,” I said, “it wouldn’t be about love.”

“You can’t be sure,” Susan said. “Human emotion is sometimes very convolute.”

“I’ve heard that,” I said.

Susan smiled and drank some coffee.

“How about Gary Eisenhower?” she said.

“You think he might do that?” I said.

“No,” Susan said.

“Shrink insight or woman’s intuition?” I said.

“Sometimes there’s not much difference,” Susan said.

“I don’t think he did it, either,” I said.

“Gumshoe insight?” Susan said. “Or male intuition?”

I grinned at her.

“Sometimes,” I said, “there’s not much difference.”

“Does he have an alibi?” Susan said.

“Don’t know,” I said. “Belson was supposed to interview him today.”

“So,” Susan said, “pending what you get from Belson, if it wasn’t Gary, who did the actual shooting?”

“Damn,” I said. “You don’t know that, either?”

“Sorry,” Susan said.

“And you a Harvard Ph.D.”

“I know,” Susan said. “Puzzling, isn’t it.”