IT WAS A LITTLE AFTER NINE in the morning on an overcast day with some thin fog in the air. I was drinking coffee and reading “Arlo & Janis” when Nancy Sinclair came carefully into my office, as if she was entering the confessional.

“Mr. Spenser?” she said. “I’m Nancy Sinclair, from the other day at Elizabeth Shaw’s office?”

“Of course,” I said.

As far as I could recall, she had not spoken when we had our meeting. She looked like a dressed-up cheerleader: a plaid skirt and a white shirt, dark stockings and boots. She was small. Her hair was short and thick. Her jewelry was gold and simple, and so was her wedding band. Her eyes were blue and very big, and she seemed to have a look of permanent surprise, as if the world amazed her. She sat opposite me, in front of the desk, with her knees together and her hands folded in her lap. She didn’t say anything.

“How ’bout them Sox?” I said.

She smiled brightly.

After a while I said, “How you doing?”

“Fine.”

“Is there something you’d like to discuss?” I said.

She nodded.

“Is it about Gary Eisenhower?” I said.

She nodded again. I waited. She smiled at me hopefully. I nodded helpfully.

“I love my husband,” she said.

“That’s nice,” I said.

“He loves me,” she said.

“Also nice,” I said.

“We love each other,” she said.

“Good combo,” I said.

“I don’t…”

She seemed to be thinking of how to say whatever it was she wanted to say.

“I don’t want you to get the wrong idea,” she said.

“I’d be thrilled with any idea,” I said.

She smiled brightly again. It was what she did when she didn’t understand something. I was already pretty sure that understanding stuff wasn’t a big part of her skill set.

“I did have an affair with Gary Eisenhower,” she said. “I don’t deny it. But it was not because Jim and I don’t love each other.”

“What was it because?” I said.

She blushed slowly but pervasively. It was kind of interesting watching the blush spread slowly over her face and down her neck, and onto the small expanse of chest that her white shirt collar exposed. She looked as if she might be blushing to her ankles.

“I’m oversexed,” she said.

“Doesn’t make you a bad person,” I said.

“It does,” she said. “I keep promising myself it will never happen again. But it does. I can’t seem to stop myself.”

“So Gary Eisenhower isn’t the first,” I said.

“God, no,” she said. “I once had sex with a man who came to plow the driveway. I’m… This is so embarrassing… I’m insatiable.”

“And your husband’s not enough,” I said.

“We have a good sex life. I’m just… I’ve fought it since junior high school. I am some sort of nymphomaniac.”

I nodded.

“I think ‘nymphomania’ is sort of an unfashionable term these days,” I said.

“Whatever,” she said, her face still bright red under her makeup. “I’m addicted to sex. It is a shameful thing, and it has made my life very difficult.”

“Ever talk to anyone about it?” I said.

“I talked once with the minister at our church, before I got married.”

“And?”

“We prayed together,” she said.

“At least he didn’t ask you out,” I said.

“Excuse me?”

I shook my head.

“My mouth sometimes operates independent of my brain,” I said.

She smiled brightly.

“For a little while after we prayed together, it seemed almost as if it had worked…”

“But?” I said.

She shook her head.

“It didn’t,” she said.

Her blush had faded. She seemed now to be having an easy conversation with a casual acquaintance about a perfectly pleasant subject. No wonder the praying had worked for a while.

“But what I need you to understand,” she said, “is that I love my husband. And he loves me. To find out about me would just kill him.”

“I’ll try to prevent that,” I said.

“Have you made any progress?” she said.

“Not much. Do you ever work out at Pinnacle Fitness?”

She nodded.

“Yes,” she said. “I have a membership. Why do you ask?”

“Just looking for a pattern,” I said.

“Do you have a picture of him?” she said.

“No.”

“I do,” she said.

“May I see it?” I said.

“I took it when he was asleep,” she said, “with the camera in my telephone.”

“He doesn’t know?” I said.

“No.”

She took an envelope from her purse.

“It’s a bit salacious,” she said.

“Me, too,” I said, and put my hand out.

She smiled brightly again and handed me the envelope. I opened it. In the envelope was a computer printout of a digital photograph of a naked man lying on his back on a bed in what was probably a motel room. It was not my kind of salacious. And even if it had been, Nancy had edited out the groin area with a Magic Marker.

Decorum.

ALL OF MY CLIENTS were members of Pinnacle Fitness. Which was a pattern. Which gave me something to do. Of course they might also have gone to the same gynecologist, or belonged to the same square-dance club. But a pattern was a pattern. And it was better than having nothing to do. So I walked over to Tremont Street and took a look.

The club was on the top of a newish building across Tremont Street from the Common. Until I was a grown man, I had never even been in any place as glossy as Pinnacle Fitness. It was a monument to the fitness illusion that somehow working out was fun and glamorous. I thought about the gyms where I’d trained as a kid, when I was a fighter. I had started in Boston at Henry Cimoli’s decrepit dump on the waterfront, when the waterfront was decrepit. Henry used to say the location was perfect for screening out the frauds, because only a legitimate tough guy would dare to go down there. Then the waterfront yuppified and so did Henry, and when I went there now I felt sort of misanthropic for not wearing spandex. But there are things that can’t be compromised. I refused to dress up to work out.

The lobby of Pinnacle Fitness had sofas and coffee tables and a snack bar where you could get juices and smoothies and tofu sandwiches on seven-grain bread. It was probably not a good place to get a linguica sandwich. I went to the front desk.

“Gary Eisenhower here?” I said.

The young woman at the front desk had a blond ponytail and very white teeth. She was wearing a white polo shirt with the club logo on it and black satin workout pants.

“Excuse me?” she said.

“Gary Eisenhower,” I said. “Is he here?”

“Does he work here?”

“I don’t know,” I said.

She frowned cutely.

“I don’t believe we have anyone by that name working here,” she said.

“Oh,” I said. “Good. So he’s a member, then?”

“I, ah, I don’t recognize the name,” she said.

“Could you look him up for me?” I said.

“I… I’m sure the client-services manager can help you,” the young woman said. “That’s her office right there.”

The client-services manager had an open-door policy. I knocked on the open door and she turned in her swivel chair and smiled at me radiantly and stood. She, too, had a blond ponytail and very white teeth. But she was wearing a white top and a black skirt. The skirt was short, and there was a lot of in-shape leg showing between the hem and the top of her black boots.

“Hi, I’m Margi,” she said. “How can I help you?”

“I’m looking for Gary Eisenhower,” I said.

“Is he a member here?” Margi said.

“That’s what I was going to ask you,” I said.

“Why do you wish to know?” Margi said.

“I’d like to get in touch with him,” I said.

“It is club policy, sir, not to give out member information.”

“Something illicit going on here?” I said.

“Of course not,” Margi said. “It is simply that we respect our members’ privacy.”