You’re a terrific snob, Greer, her husband, Tag, is fond of saying. Greer fears that this is true. But where Benji’s wedding was concerned, she had to intervene. Look what she’d endured when Thomas married Abigail Freeman: a Texas wedding, with all of Mr. Freeman’s oil money on grand, grotesque display. There had been three hundred people at the “welcome party” at the Salt Lick BBQ—Greer had hoped to live her whole life without ever patronizing a place called the Salt Lick BBQ—where the suggested dress code was “hill-country casual,” and when Greer asked Thomas what that could possibly mean, he’d said, Wear jeans, Mom.

Wear jeans to her elder son’s wedding celebration? Greer had opted for wide-legged ivory trousers and stacked Ferragamo heels. Ivory had turned out to be a poor choice, as the guests of this welcome party had all been expected to eat pork ribs with their fingers. Shrieks of joy had gone up when there had been a surprise appearance by a country singer named George Strait, whom everyone called “the King of Country.” Greer still can’t imagine how much it must have cost Mr. Freeman to hire the King of Country—and for an event that wasn’t even part of the usual nuptial schedule.

As Greer drives the Defender 90 (Tag had it rebuilt and shipped over from England) down to the Hy-Line ferry to pick up Celeste’s parents, Bruce and Karen Otis, she sings along to the radio. It’s B. J. Thomas’s “Hooked on a Feeling.”

This weekend, Greer is effectively the bride’s mother as well as the groom’s, for she is 100 percent in charge. She hasn’t encountered one iota of resistance from anyone, including Celeste herself; the girl responds to all of Greer’s suggestions with the exact same text: Sounds good. (Greer despises texting, but if one wants to communicate with Millennials, one must abandon old-fashioned notions like expecting to speak on the phone.) Greer has to admit, it has been far easier to get her way with the color scheme, the invitations, the flowers, and the caterer than she ever anticipated. It’s as if this were her own wedding, thirty-two years later… minus her overbearing mother and grandmother, who insisted on an afternoon reception in the sweltering garden of Swallowcroft, and minus a fiancé who insisted on a stag party the night before the wedding. Tag had gotten home at seven o’clock in the morning smelling of Bushmills and Chanel No. 9. When Greer had started weeping and demanding to know if he’d actually had the gall to sleep with another woman the night before his wedding, Greer’s mother took her aside and told her that the most important skill required in marriage was picking one’s battles.

Make sure they’re ones you can win, her mother had said.

Greer has tried to remain vigilant where Tag’s fidelity is concerned, although it has been exhausting with a man as charismatic as her husband. Greer has never found hard evidence of any indiscretions, but she has certainly had her suspicions. She has them right up to this very minute about a woman named Featherleigh Dale, who will be arriving on Nantucket from London in a few short hours. If Featherleigh is silly and careless enough to wear the silver-lace ring with the pink, yellow, and blue sapphires—Greer knows exactly what the ring looks like because Jessica Hicks, the jeweler, showed her a picture!—then Greer’s hunch will be confirmed.

Greer encounters traffic on Union Street. She should have left more time; she cannot be late for the Otises. Greer has yet to meet either of Celeste’s parents in person and she would like to make a good impression and not leave them to wander forlornly around Straight Wharf on this, their first trip to the island. Greer had worried about hosting a wedding so close to the Fourth of July, but it was the only weekend that worked over the course of the entire summer and they couldn’t put it off until autumn because Karen, Celeste’s mother, has stage 4 breast cancer. No one knows how much time she has left.

The song ends, traffic comes to a dead stop, and the sense of foreboding that Greer has successfully held at bay until now fills the car like a foul smell. Usually, Greer feels unsettled about only two things: her husband and her writing, and the writing always sorts itself out in the end (declining book sales aside, although, really, it’s Greer’s job to write the mysteries, not sell them). But now she worries about… well, if she has to pinpoint the exact locus of her dismay she would say it is Celeste. The ease with which Greer has been able to take control of this wedding suddenly seems suspect. As Greer’s mother used to say, Things that seem too good to be true usually are.

It’s as if Celeste doesn’t care about the wedding. At all. How had Greer ignored this possibility for four months? She had reasoned that Celeste was (wisely) deferring to—or placing extreme confidence in—Greer’s impeccable taste. Or that Celeste’s only agenda was getting the wedding planned as expediently as possible because of her mother’s illness.

But now, other factors come into focus, such as the stutter Celeste developed shortly after the date was set. The stutter began with Celeste repeating certain words or short phrases, but it has become something more serious, even debilitating—Celeste trips over her r’s and m’s and p’s until she grows pink in the face.

Greer asked Benji if the stutter was creating problems for Celeste at work. Celeste is the assistant director at the Bronx Zoo and she is occasionally called upon to give lectures to the zoo’s visitors—mostly schoolchildren during the week and foreigners on the weekends—so Celeste has to speak slowly and clearly. Benji replied that Celeste rarely stuttered at work. Mostly just at home and when she was out socially.

This gave Greer pause. Developing a stutter at twenty-eight could be attributed to… what? It was a tell of some kind. Greer had immediately used the detail in the novel she was writing: the murderer develops a stutter as a result of his guilt, which grabs the attention of Miss Dolly Hardaway, the spinster detective who is the protagonist of all twenty-one of Greer’s murder mysteries. This is well and fine for Greer, who tends to mine every new encounter and experience in her fiction, but what about in real life, for Celeste? What is going on? Greer has the feeling that the stutter is somehow connected to Celeste’s imminent marriage to Benji.

There’s no time to think any further because suddenly traffic surges forward and not only does Greer move swiftly into town, she also finds a parking spot right in front of the ferry dock. She still has two minutes to spare. What magnificent luck! Her doubts fade. This wedding, this union of two families on the most festive of summer weekends, is clearly something that’s meant to be.

KAREN

Viewed from a distance, Nantucket Island is everything Karen Otis dreamed it would be: tasteful, charming, nautical, classic. The ferry passes inside a stone jetty, and Karen squeezes Bruce’s hand to let him know she would like to stand and walk the few feet to the railing now. Bruce places an arm across Karen’s back and eases her up out of her seat. He’s not a big man but he’s strong. He was the Pennsylvania state champion wrestler at 142 pounds in 1984. Karen first set eyes on him sitting in the Easton Area High School pool balcony. She was swimming the butterfly leg for the varsity relay team, which routinely practiced during lunch, and when she climbed out of the water, she spied Bruce, dressed in sweatpants and a hooded sweatshirt, staring at an orange he held in his hands.

“What is that guy doing?” Karen had wondered aloud.

“That’s Bruce Otis,” Tracy, the backstroker, had said. “He’s captain of the wrestling team. They have a meet this afternoon and he’s trying to make weight.”

Karen had wrapped a towel around her waist and marched up the stairs to introduce herself. She had been well endowed even as a high-school sophomore and was pretty sure the sight of her in her tank suit would take Bruce Otis’s mind off the orange and his weight and anything else.

Bruce holds Karen steady and together they approach the railing. People see them coming, take note of the scarf wrapped around Karen’s head—she can’t bring herself to do wigs—and back up a few steps to make a respectful space.

Karen grips the railing with both hands. Even that is an effort but she wants a good view for their approach. The houses that line the water are all enormous, ten times the size of Karen and Bruce’s ranch on Derhammer Street in Forks Township, Pennsylvania, and these houses all have gray cedar shingles and crisp white trim. Some of the homes have curved decks; some have stacked decks at nifty angles like a Jenga game. Some have lush green lawns that roll right up to stone walls before a thin strip of beach. Every home flies the American flag, and all are impeccably maintained; there isn’t a dumpy or disheveled renegade in the bunch.