Sadie? Not likely.

At the farm, he bought Harper a cup of coffee, and they sat and talked, and it was the happiest hour Reed had passed in some time. Two weeks later, when Reed asked Harper to go for a drink, it was a spur-of-the-moment decision but also one he’d been considering since they parted ways at Morning Glory Farm. Reed knew it was a risk—going for drinks (which turned out to be dinner as well) with a patient’s daughter—but until they walked out of Atria that night, Reed was still able to tell himself they were only friends. Reed had a populated life—his patients, his colleagues at the hospital, his wife’s family—but he hadn’t had a friend since medical school except for Sadie. And now, it was safe to say, Sadie was no longer his friend.

Reed had started kissing Harper—why? Because the night air was finally crisp after such a hot summer? Because he was high from the wine, the food, the companionship? Because at dinner Harper had unwittingly brushed his shoulder and knocked her knee against his? The circumstances demanded it, Reed thought later, when he tried to rationalize his actions. But that was cowardly. The decision hadn’t been foisted upon him by outside “circumstances.” The decision had been consciously made. By him.

Once Reed had kissed Harper, once he had made love to her in the backseat of his car—well, the genie could not be put back into the bottle. He thought about her nonstop. At first it was only sexual. His brain was engulfed in a fug of overwhelming desire for an act that he had been so long denied. A few weeks in, however, there were intimate conversations and the inevitable sharing of histories, and Reed realized that Harper was an extremely complex human being. He heard about her upbringing, her parents, her identical twin, her elite private school, her rarefied life in a town house on Beacon Hill. But then that particular storybook ended. Her parents divorced, Harper attended Tulane, then moved to Martha’s Vineyard to live with Billy. Reed heard about her series of jobs: scooping ice cream, selling carousel tickets, landscaping for Jude Hogan—and one or two nights a week, serving drinks at Dahlia’s. Reed was both proud and ashamed to say that he had never set foot in that particular establishment; it was rumored to be a hotbed of cocaine, infidelity, and summer money. Harper had fallen prey to the scene; she had agreed, on one occasion, to deliver a package for Joey Bowen. She had not known there would be any danger, but she had ended up handcuffed and lying facedown on a client’s lawn. There was a fair amount of public shame, she told him. Reed pointed out that it might have been worse; she could have ended up in jail. Harper said she would rather have served her time. Instead the citizens of the island seemed determined to make her pay in other ways.

Reed and Harper saw each other once a week at first, then more often. But when the weather started to warm up, Harper became less available. Reed then discovered that she had started dating an Edgartown policeman, the young, charismatic, well-connected Drew Truman. Reed couldn’t believe the way this discovery pierced him. He had never in his life felt so jealous. He realized he had no right; they had made no promises. But he didn’t care. He couldn’t stand the thought of Harper with anyone else. He left the hospital midshift and showed up at her duplex and demanded that she break things off with Drew.

She had laughed in his face.

Dr. Reed Zimmer, a pillar of the hospital, if not the community, found himself caught in a conundrum commonly experienced by lesser men. He was in love with someone other than his wife but unsure if he had the gumption to leave his marriage. To leave would bring pain, shame, scrutiny. He didn’t think he could stand it; he liked being held in high regard—which was, he realized, a character flaw in itself.

Reed had allowed himself to believe that he was invincible. Unlike every other unfaithful man in the history of the world, he would not get caught. He would stay with Harper until Sadie left of her own accord, and surely that would be soon. Sadie was as miserable in the marriage as he was. In the spring, she started talking a lot about Tad Morrissey, the Irish carpenter who worked with Franklin. Tad was wonderful, Sadie said. Tad had come to the pie shop to build some new shelves, and he had shimmed the back door, which Sadie always had a hard time closing in the summer.

Reed convinced himself that Sadie was having her own affair—with Tad Morrissey. Was there anything wrong with that? Reed wondered. He and Sadie were both being discreet, keeping up appearances. They went together to the start-of-summer barbecue at Lambert’s Cove with Sadie’s family. Reed liked Sadie’s family: her parents, Al and Lydia; her brother, Franklin. Lo and behold, Franklin brought Tad Morrissey with him to the barbecue as his “date,” he joked—but really, Reed suspected, Tad was Sadie’s date. Possibly Franklin knew about Sadie, and Tad was in on the deceit. Certainly no one batted an eye when Sadie sat next to Tad by the fire or when Sadie jumped up to fetch Tad more potato salad.

“While you’re up, I’ll have a little more as well,” Reed had said. But Sadie had pretended not to hear him.

Sadie only paid attention to him that night when he was checking his text messages—and when he stepped away from the fire to call Harper back.

“Where are you going?” Sadie asked. “You’re not on call tonight.”

“I had a patient die unexpectedly,” Reed said. Lydia heard this and crossed herself. Sadie rolled her eyes, which only showed how much her contempt for him was spoiling her soul. She turned away, asked Tad if he wanted another beer, and Reed was free to talk to Harper.

He should never have met her at Lucy Vincent. In retrospect, that much was obvious. But Billy had died, and Reed was taken as much by surprise as she had been. Billy had congestive heart failure and myriad other ailments, but Reed had thought he would last weeks longer, maybe even the entire summer. Some people had a dogged survival instinct, and Billy Frost was one of them. He had seemed like the kind of man who could live forever, despite his terminal condition.

Reed had thought Sadie was asleep when he left the house. She had been in their bedroom with the door closed, the lights out. Reed no longer kept any clothes or belongings in that room, so there would be no reason for him to open the door and check on Sadie; if she was awake, she would think he was coming after her for sex. They had both had a lot to drink at the barbecue, and whereas this sometimes led to a fight, on the ride home Sadie had been benign, nearly kind—the result, Reed assumed, of spending an evening in close proximity to her beloved.

He eased the Lexus out of the driveway, feeling like a teenager sneaking out from a house ruled by overbearing parents. Once he hit South Road, he experienced a heady sense of freedom. He was alive. How many moments of how many days had he failed to realize that? If someone had asked him then if he had any intention of going back to Sadie that night or ever again, he might have shrugged and said, What for?

Sadie had trailed him. She had heard the car pull out—or perhaps she had sensed something, overheard part of his conversation with Harper, read some impending deception on his face—and jumped out of bed. Possibly she had been waiting for him to go to bed so she could sneak out to meet Tad. However it had happened, he had been caught with Harper in the parking lot of Lucy Vincent.

Caught.

At first he thought he could talk his way out of it, using a measured voice and reasonable calm. Sadie had been quite drunk; her eyesight wasn’t reliable. It had been dark, and she was without her glasses.

But Sadie had embarked on a full-blown investigation, which Reed, unfortunately, didn’t discover until after Sadie made the abhorrent scene at Farm Neck. In the days that followed Billy Frost’s memorial reception, the affair between Harper Frost and Dr. Reed Zimmer was all anyone talked about. It made Reed queasy to think about how lurid and trashy his private life must seem, that he had been revealed to be just one more faithless slug. A cheater.

Sadie forced Reed to go to his in-laws’ house, in Katama, to confess. Al Phelps had cast his eyes to the floor, uncomfortable and embarrassed at hearing Reed’s admission of guilt. Lydia had cried as though she were the one Reed had betrayed.

“Shame on you,” she’d whispered.

Reed would have liked to explain how bad things were at home, that Sadie wouldn’t sleep with him, wouldn’t accept a cup of coffee from his hands, wouldn’t kiss him good-bye when he left for work. But what did that matter? There were two kinds of people: the faithful and the unfaithful. He was unfaithful. And he had blithely chosen to believe that his wife was also unfaithful. He had created a whole fantasy relationship between her and Tad Morrissey, which, he realized now, was only for the benefit of his aching conscience.