Both Sharon and Romeo receive invitations but Sharon is in a quandary: Her sister, Heather, will be visiting over the Fourth. “I notice these invitations don’t include a plus-one like the Pink and White Party did,” Sharon says to Romeo over the phone. Since the day of the boat ride, they’ve been in constant communication, texting every few hours, talking on the phone each night before bed.

“Thank god my plus-one is already invited,” Romeo says.

That’s sweet, Sharon thinks. But what will she do about Heather? She calls Leslee Richardson. “My sister, Heather, will be visiting,” Sharon says. “Is there any way I might bring her along?”

“I’m so sorry,” Leslee says. “Numbers on the boat are limited.”

“I completely understand,” Sharon says.

“Will you not be able to make it, then?” Leslee asks. “I’m sure you want to spend time with your sister.”

Sharon pauses. She knows she should offer her regrets and hang out with Heather, but the idea of missing the party—with Romeo—is too much to bear. “Don’t be silly,” Sharon says.

Eric and Avalon are invited on the sail, but they decline. They’re going to drive out to Coatue and grill clams on their hibachi.

“Do you want to join us?” Avalon asks Kacy.

“Coco wants me to come on the sail,” Kacy says, “and I think it sounds like fun.”

“Well,” Avalon says evenly, “if it’s anything like the Pink and White Party, I’m sure you’ll have stories for us.”

The theme of the sail is American Summer, and those of us invited dress accordingly. We board Hedonism on Swain’s Wharf and each of us is immediately handed a cocktail called the firecracker, which is a layered drink: red on the bottom (grenadine), white in the middle (vodka and lemonade), and blue curaçao on top.

Has any cocktail that includes blue curaçao ever tasted good? Coco believes the answer is no, but Leslee insisted on this drink for the wow factor, and people seem to be slurping them right down. Coco will have to handcraft another round, but because space on the boat is limited, she’s in charge of passing the hors d’oeuvres that Zoe Alistair’s team dropped off: pigs in a blanket, classic shrimp cocktail, and corn and lobster fritters with a seeded mustard dipping sauce.

Kacy says, “Do you want help?”

“I’ll find you during the fireworks,” Coco says.

“What’s good with you and Lamont?” Kacy asks. “Are you linking?”

“No,” Coco says truthfully. Since they were caught on Whale Island, Lamont has been avoiding her. Coco texted him to ask if everything went okay getting the boat back; he responded that it was fine—neither Leslee nor Bull noticed the boat had been missing—but they shouldn’t try that again.

It was poor form. The Richardsons aren’t paying us to hang.

Right, Coco thought. They broke “the rule,” and bumping into Kacy spooked him; news of their adventure could easily have gotten back to Bull and Leslee.

Can we hang out off-property sometime? she texted. There’s an entire island past the end of the driveway.

Three dots arose; he was typing. She waited for his response, but none came.

Coco hasn’t seen Lamont except in passing since then, but she thinks maybe tonight, they can reconnect. When she finishes making the first tray of drinks, she offers one to Lamont. “Firecracker?”

“You’re kidding, right?” he says. “I’m the captain, Coco.”

“Okay,” she says. “Sorry.”

Fast Eddie boards the boat with a new confidence. Their offer for Jeanne Jackson’s property was accepted and signed. In a few weeks, they’ll sign the purchase and sale agreement; Bull will wire the money, and they’ll break ground. Grace was initially livid that Eddie was getting back into real estate development, but she calmed down when he told her that Addison Wheeler was involved and that Bull Richardson was financing the entire thing as an equal partner. In Grace’s eyes, the Richardsons can do no wrong.

Grace is wearing a new dress to the party, a slinky red thing with a low back and a slit up the front. Eddie would like to believe Grace wants to look good for him, but when he sees Benton Coe over on the port side holding a cocktail and talking with Leslee Richardson—who is, frankly, fawning all over the guy—Eddie wonders if Grace knew he would be here. Oh, how Eddie wishes Benton were one of the people who’d gotten axed from the Richardsons’ guest list. No such luck.

Sharon and Romeo arrive at the party together, and the first person who notices is Busy Ambrose from the Field and Oar Club. “Are you two an item, then?” she asks. Instead of looking happy for Sharon, she appears perplexed. Busy is a terrible snob, and Romeo, “the Steamship guy,” falls beneath her consideration.

“We are!” Sharon says. “And we’re very happy, thanks.”

Sharon is wearing snug white pants, a navy-and-white-striped halter, and the cutest red jean jacket that she’d asked her sister, Heather, to pick up from the Saks in Chevy Chase. “You look adorbs,” Heather said in the minutes before Romeo arrived. “And very on-theme.” Sharon had worried that Heather might be miffed about Sharon going to the party without her, but Heather was thrilled to have a night at home. Sterling and Colby were going to a bonfire, so Heather and Robert planned to order from Pi Pizzeria and “hang out”—which meant, Sharon knew, that Robert would watch MrBeast on YouTube and Heather would work.

“What’s the name of the couple throwing the party again?” Heather asked.

“The Richardsons,” Sharon said. “Bull and Leslee.”

The name Bull Richardson sounded familiar to Heather, though she wasn’t sure why.

Delilah tries to resist having fun, but that’s impossible. She helps herself to a firecracker cocktail and joins a tour of the living space below deck. The boat is glamorous—so much creamy leather and gleaming mahogany, so many king beds sheathed in navy and white linens, so many huge bouquets of lilies and Dutch hydrangeas from Flowers on Chestnut. Back on deck, Delilah pops a crispy corn and lobster fritter into her mouth and feels a surge of excitement as the motor starts and the Valladares brothers, Javier and Esteban, who are crewing tonight, gather the lines and push them off the dock. She sees Leslee across the way talking to the Chief and Andrea, but as soon as Delilah approaches, Leslee says, “I have to check on the buffet, and the music should be louder, don’t you think?” and disappears with a wave.

The Chief turns to Delilah. “I heard you were a real bulldog at pickleball the other day,” he says.

Lamont Oakley and the Valladares brothers raise the sails as we exit Nantucket Harbor. The only sight more majestic than the sails billowing against the setting sun as seen from below might be Hedonism in full sail as seen from a neighboring boat.

Blythe Buchanan and her wife, Linda, have motored over from Cape Cod in their thirty-eight-foot Regal, Dawg Daze II, to watch our fireworks as they do every year. As Hedonism sails by, some people wave, and Blythe and Linda wave back. But a second later, Blythe nearly chokes on her spicy margarita.

“Did you see who was on that boat?” she asks.

Linda is a step ahead of her, using the MarineFinder app to figure out who owns Hedonism. “Lord have mercy,” she says. “Bull and Leslee Richardson bought it.” Linda and Blythe met the Richardsons in Palm Beach, and oh, boy, do they have stories.

Blythe groans. “Nantucket better watch out.”

Back at Blond Sharon’s house, Heather is working on a case, but she takes a quick break to google the couple throwing the party. Neither Bull nor his wife seem to be active on social media, though Heather finds Bulfinch Richardson’s LinkedIn profile. He owns Sweetwater, a beverage-distribution company that’s somehow also a Hollywood production company. (There are credits for movies Heather has never heard of.) When Heather digs a little deeper, the name clicks—the SEC did a preliminary investigation into Sweetwater Distribution. The company owns a bottling plant and a plastics factory that manufactures the bottles. A whistleblower called them out for environmental infractions and for misleading greenhouse-gas-emissions disclosures. But had anything come of it? Heather is going to check when she returns to the office.

Heather sends Sharon a text: How’s the party? Heather needs to be careful. Her sister is the biggest gossip on the island and anything Heather tells Sharon about Bull’s business will be all over Nantucket quicker than you can say Vanderpump Rules.

It’s divine! Sharon texts back. Then another text comes in, a photo of Sharon with a red carnation clenched between her teeth and Romeo in an Uncle Sam hat. They’re both holding sparklers.

Bull’s company must have been cleared of any wrongdoing, Heather thinks. Just because he was investigated doesn’t mean he broke the law. The Richardsons are allowed to have fun; as the sound of the first fireworks remind Heather, it’s a free country. She won’t say anything to Sharon about the Richardsons, she decides. After all, they’re not dangerous. It’s not like they’re going to hurt anyone.

Hedonism anchors off Jetties Beach, where those of us not invited to the Richardsons’ party have gathered to watch the fireworks. We hear the music pumping: “Born in the USA,” then Katy Perry’s “Firework.” Everyone on board is whooping and dancing; we hear the distinct pop of a champagne cork.

Dr. Andy McMann and his wife, Rachel, are hunkered down in the sand eating takeout sushi and drinking a very nice white Bordeaux, but even so, Dr. Andy sees Rachel staring at Hedonism with longing. “Don’t look,” he says.

But it’s like worrying a loose tooth (a behavior Dr. Andy knows only too well). Rachel can’t help herself.

Eric and Avalon can see Hedonism from their spot on the second point of Coatue. Eric pulls clams off the grill, and Avalon drags the smoky gems through melted butter. She washes the clams down with a cold beer, then lies back on the blanket next to Eric and counts the emerging stars.

She hears music—the entire island is being treated to the Richardsons’ soundtrack—and snuggles against her boyfriend, digging her feet into the cool sand. The first firework whistles, pops, and explodes in a burst of silver and gold above them. A chorus of happy screams goes up from the boat. Avalon is so glad she’s not on it.

Coco can’t wait for this party to be over. She’s in charge of setting up the buffet—fried chicken, ribs, potato salad, coleslaw, baked beans, homemade pickles, and biscuits with honey butter—and then cleaning it all up. While she’s collecting plates and trash, she finds a sparerib sticking out from between two of the cushions of the ivory sofa in the living area. Who does something like that? She moves on to setting up the miniature pies—cherry, blueberry, peach, pecan, and banana cream—that Leslee had flown in from a place called Peggy Jean’s in Columbia, Missouri.

Coco hears the fireworks begin and thinks, Thank god, the end is near. When she goes above deck, her Leslee radar kicks in. Coco likes to know where her boss is at all times. First she checks the captain’s wheel because, as she’s learned, Leslee tries to stay as close to Lamont as possible, but Lamont is talking to his crew, Javier and Esteban. Javier is a senior at Nantucket High School, Esteban a junior; they’re both on the sailing team. Just like Lamont was, Javier told Coco when she met him. They’re listening to Lamont like he’s Captain America.