What kind of crazy advice was that? If it was unexpected, how would Sharon know where to look for it?

The meaning of Heather’s words lands on Monday at the Field and Oar Club. Sharon has just finished a tennis lesson with the new instructor, Mateo, who came to the Field and Oar from Buenos Aires. Mateo has the cheekbones and eyebrows of a luxury-brand model and he thought nothing of wrapping his strong arms around Sharon in an attempt to fix her backhand. A stranger comes to town, part three? she thinks. However, even Sharon knows that lusting after her hot tennis instructor isn’t exactly “unexpected.”

In the ladies’ lounge after her lesson, Sharon is mindlessly emptying her bladder when she hears a woman cry out. Not in fright or pain, Sharon doesn’t think, but in frustration. Sharon pokes her head around the corner to find out what’s going on—expressions of genuine emotion are rare at this club—and sees Delilah Drake squashed into one of the club chairs like a pea smashed into a rug.

“Delilah?” Sharon says. She doesn’t quite consider Delilah a friend, though they’ve known each other forever and are connected through various filaments of the Nantucket web. Delilah is married to Jeffrey Drake; they own Sea View Farm, where Sharon buys her tomatoes and her corn. Delilah is close with Phoebe Wheeler and Andrea Kapenash, and their friend group has a name—the Outcasts? The Commitments? Sharon is guilty of making fun of the name, whatever it is, but that’s just because she’s envious. They are three smart, fun, accomplished women and Sharon has always wanted to know them better.

The other unexpected thing about finding Delilah here is that Delilah isn’t a member of the Field and Oar Club. Sharon sits on the membership committee, and although she always votes to admit the Drakes, the motion never carries.

“Is everything okay?” Sharon asks. The answer is obviously no, but will Delilah spill the tea? Delilah sinks farther into the chair, her green dress billowing around her like a parachute.

Sharon sits on the sofa and props her sneakered feet up on the white wicker coffee table, pretending she needs to take a load off after an exhausting tennis lesson. Sometimes the best way to get people to talk is to be quiet.

Delilah says nothing for a moment and Sharon thinks, Fair enough. Sharon isn’t exactly known for her discretion. She wonders how to describe the color of Delilah’s dress. It’s not lizard or haricot vert; she considers kaffir lime, shamrock, and emerald, but all of those make the color sound more appealing than it is. Traffic-light green, maybe?

Finally, Delilah exhales. “Have you met Leslee Richardson?”

“No,” Sharon says. Cautiously dropping her voice to a whisper, she adds, “But I’ve heard some things.”

Delilah leans forward. “What have you heard?”

Delilah is turning the tables, but as Sharon knows, you must often give information to get information. “She and her husband bought Triple Eight Pocomo, and then a few days later, a yacht, Hedonism.” Sharon laughs. “Sounds like the name of a nudist colony. And I did hear… I can’t say from whom… that she considers herself a ‘party animal.’” The term is so ridiculous, Sharon uses air quotes. “I also heard she’s very eager to become a member here.”

Delilah takes a breath to speak, then hesitates. “This has to stay in the vault.”

Surely she’s being ironic, Sharon thinks. Everyone on Nantucket knows she is constitutionally unable to keep a secret. But maybe this once, to preserve the integrity of her character study, she’ll try? “In the vault!” Sharon agrees.

Delilah starts to talk: Leslee Richardson is here having lunch with Phoebe, Andrea, and Delilah. She has managed to completely ingratiate herself with Phoebe, even offering to help Phoebe’s son, Reed, get into his first-choice boarding school.

“Have you ever heard of anything so transactional?” Delilah says. “She offered because Phoebe is apparently writing the Richardsons a nominating letter to join the club.”

“What?” Sharon says. She is offended on Delilah’s behalf. “There’s a long wait list.” She nearly adds: As you of all people know.

“Leslee strikes me as one of these silky-smooth operators,” Delilah says. “She’s talking about all the parties she’s going to throw at her house and on the yacht. She wants to be our fourth in pickleball.”

Sharon nearly says, I play pickleball if you’re looking for a fourth, but she doesn’t want to sound like what her twins refer to as a “Pick-Me girl.”

“The weird thing is how quickly she’s infiltrated,” Delilah says. “She and the husband, Bull, are out at the restaurants seven nights a week, making connections with every round of drinks they buy. They hired Lamont Oakley as their boat captain.”

“That was a coup,” Sharon admits. “Everyone loves Lamont.”

“Exactly,” Delilah says. “He’s going to lend them legitimacy, but the truth is, nobody knows anything about these people.”

“Where did they come from?” Sharon asks.

“We asked, but Leslee only said they’ve been bouncing around. She mentioned the Virgin Islands, Palm Beach, Aspen…”

“All the hot spots,” Sharon says. “And now they’ve landed in the most exclusive place of all.”

Delilah seems to relax a bit. “It’s not like they have to provide references to live here,” she says. “I just think it’s odd the way they’ve decided to make Nantucket their forever home without any context. I feel strangely threatened, like I’m in middle school and Leslee is the new girl who shows up and steals away my friends. Though I do like her perfume. She smells like crème brûlée.”

Now, that’s a detail! Sharon thinks as she mentally writes the scene: Delilah’s green dress reflects the jealousy she feels about this interloper; Phoebe succumbs to Leslee’s sequined promises and her vanilla-and-burned-sugar scent. How did Andrea react to Leslee Richardson? Sharon wonders. She probably found some middle ground, reserved judgment; Andrea is known for being sensible and measured.

Suddenly Delilah stands, so Sharon does as well. “I’d better get back out there before they start talking about me,” Delilah says.

Sharon laughs, though that’s probably exactly what’s happening. “Thanks for the warning about Madam Richardson.” She wants Delilah to know that she can count on her as an ally—though maybe not too much of an ally because Sharon would like to get invited to the parties at 888 Pocomo Road and on the yacht.

“I’m sure she’s not as bad as I’ve made her out to be,” Delilah says. She tugs on the sides of her dress. “She’s probably harmless.”

“Well,” Sharon says, “that would be a disappointment.”

Delilah gives Sharon a hug before she disappears out the door. Sharon is tempted to poke her head out onto the patio so she can get a look at Leslee Richardson in person, but in the end, she decides to go straight home. She needs to start writing while it’s all still fresh in her mind.

11. Thursday, August 22, 9:00 P.M.

When Nantucket’s incoming chief of police, Zara Washington, and Sergeant Kevin Dixon do their preliminary questioning of the guests who were on the Richardsons’ yacht, they find something odd: Most people know the Richardsons only slightly and some not at all.

“I was getting a pedicure next to Leslee at the RJ Miller Salon,” a woman named Marla Sofia says. “We got to chatting, she seemed very nice, and the next thing I knew she was inviting me and my husband, Tony, on tonight’s sail. But I wouldn’t say I know them.”

Sergeant Dixon talks to a couple who met the Richardsons while they were all singing at the Club Car’s piano bar. They’re tourists, here for three days.

A guest named Celadon Morse had taken the mat next to Leslee at a Forme Barre class and scored an invite. “I was thrilled!” Celadon says. “I’ve been hearing about these parties from everyone I know all summer long, but when I got here, I didn’t recognize a soul.” She pauses. “Except for that woman over there. She belongs to the Field and Oar Club. She has a funny name.”

“Thank you,” Zara says, and she approaches the woman, who is masked and giving Margaret Thatcher vibes—she has a severe bob and blue eyes that are watering from the smoke. When Zara asks her name, she lowers her mask and says, “Busy Ambrose.”

“And you live here on Nantucket, ma’am?”

“I’ve summered on Nantucket since the sixties,” Busy says. “I live on Ash Lane and I’m the commodore of the Field and Oar Club.”

Zara is impressed that the yacht club here has a female commodore. “I’m Zara Washington, the new chief of police.”

“Yes,” Busy says. “I read about your hiring in the paper.”

“Do you know the Richardsons, ma’am?”

“I do indeed,” Busy says. “I befriended them earlier this summer.”

“Do you know the missing woman?”

“Her name is Coco,” Busy says. “She works for the Richardsons.”

“Do you remember seeing Ms. Coyle on the boat?” Zara asks.

“Yes, she was serving drinks and passing hors d’oeuvres.”

“What was she wearing?”

“Her uniform—a pink polo shirt and white shorts.”