A small brown mongrel dog ran from the front of the house and bounced over to us. Clark tickled it behind the ear, and it responded by trying to climb onto his lap. I wished it luck. Given its size, it would have required a rope and climbing gear to ascend Mount Clark. The effort left mud stains on his pants, so he sent it on its way. The dog peered at me, wagged its tail uncertainly, and retreated. Perhaps its mistress had told it about me. If so, I was lucky it hadn’t bitten my ankle.

“I met Mara Teller at a conference in Boston,” said Clark. “She was at the bar late on the second night, we got to talking, and one thing led to another. We had sex in my room, after which she returned to hers. We didn’t see each other again at the event.”

“Did you exchange numbers?”

“No.”

“Why?”

“It was a one-shot deal for both of us. I wasn’t looking for anything more and I don’t think she was either. Plus, I felt bad about it later. Despite appearances, I cared about my wife. I still do. It doesn’t mean I can forgive her, but I don’t want her to suffer.”

I didn’t bother to congratulate him on his magnanimity.

“But you did meet Mara Teller subsequently,” I said.

“Yes, about a month later. I had business in Boston, and our paths crossed at Faneuil Hall.”

“Unplanned?”

“Yes.”

“That’s quite a coincidence.”

“Maybe it was fated.”

“Maybe it was. Fate can be accommodating that way.”

“And, you know—”

“One thing led to another,” I said. “Again.”

“Something like that. Things had grown worse between Colleen and me. The second time with Mara, I didn’t feel so bad about it. In fact, I didn’t feel bad at all.”

“Did you arrange to continue the relationship?”

“We talked about it,” said Clark, “and this time we did exchange numbers. We spoke regularly on the phone, and hooked up once or twice more.”

“Which was it, out of curiosity?”

“What?”

“Once, or twice?”

“Twice. The novelty was already fading for both of us, and Henry had been born. Then Colleen discovered the calls, along with the text messages on my phone, and confronted me with them. I didn’t try to lie, and admitted everything. By then, I was convinced our marriage was heading for the rocks, child or no child, and I recognize that I was seeking to accelerate the collision. Colleen and I had a pretty miserable couple of weeks until things started to level out, or they did for me because I was moving toward a decision. I was looking for an exit, but Colleen wanted us to stay together.”

“Did you tell her you felt differently?”

“Not at first. I tried to go along with her way of seeing the marriage—as one that still had some hope of survival—but my heart wasn’t in it. I was doing it for Henry’s sake more than anything, but Colleen and I being unhappy wasn’t going to help my son in the long run. I don’t know how it dragged on, but somehow it did.”

“Do you still have Mara Teller’s number?”

“It’s not hers anymore. The number went out of service for a while, and now it’s someone else’s.”

“So you tried getting in touch with her?”

“I did, mainly to explain what was happening in my marriage.”

“Mainly?”