Welcome to the most tumultuous summer of the 20th century. It's 1969, and for the Levin family, the times they are a-changing. Every year, the children have looked forward to spending the summer at their grandmother's historic home in downtown Nantucket. But like so much else in America, nothing is the same.

A brilliant female codebreaker. An “unbreakable” Japanese naval code. A pilot on a top-secret mission that could change the course of WWII. The Codebreaker's Secret is a dazzling story of love and intrigue set during America’s darkest hour.

Irene Steele shares her idyllic life in a beautiful Iowa City Victorian house with a husband who loves her to sky-writing, sentimental extremes. But as she rings in the new year one cold and snowy night, everything she thought she knew falls to pieces with a shocking phone call: her beloved husband, away on business, has been killed in a helicopter crash. Before Irene can even process the news, she must first confront the perplexing details of her husband's death on the distant Caribbean island of St. John.

Franny Doyle is having the worst day. She’s been laid off from her (admittedly mediocre) job, the subway doors ripped her favorite silk dress to ruins, and now she’s flashed her unmentionables to half of lower Manhattan. On the plus side, a dashing stranger came to her rescue with his (Gucci!) suit jacket. On the not-so-plus side, he can’t get away from her fast enough. Worse yet? Someone posted their (entirely not) meet-cute online. Suddenly Franny and her knight-in-couture, Hayes Montgomery III, are the newest social media sensation, and all of New York is shipping #SubwayQTs.

Six years after the fight that ended their friendship, Daphne Berg is shocked when Drue Cavanaugh walks back into her life, looking as lovely and successful as ever, with a massive favor to ask. Daphne hasn’t spoken one word to Drue in all this time - she doesn’t even hate-follow her ex-best friend on social media - so when Drue asks if she will be her maid-of-honor at the society wedding of the summer, Daphne is rightfully speechless.

In the oldest part of Stockholm, Bell Everhurst is working as a nanny for an affluent family. Hanna and Max Von Greyerz are parents to seven year-old Linus and five-year old twins Ellinor and Tilde, and Bell has been with the family for more than two years. One early spring morning, as she’s rushing out to take the children to school, she answers the phone - and everything changes. A woman from a clinic she’s never heard of asks her to pass on the message that Hanna’s husband is awake.

If she wasn’t dead already, Delphie would be dying of embarrassment. Not only did she just die by choking on a microwaveable burger, but now she’s standing in her ‘shine like a star’ nightie in front of the hottest man she’s ever seen. And he’s smiling at her. As they start to chat, everything else becomes background noise. That is until someone comes running out of a door, yelling something about a huge mistake, and sends the dreamy stranger back down to earth. And here Delphie was thinking her luck might be different in the afterlife.

Hollis Shaw, creator of the popular food blog, Hungry with Hollis, is shocked when her heart surgeon husband, Matthew, is killed in a one-car accident on a snowy morning. The cracks in Hollis’s perfect life—her strained marriage and her complicated relationship with her daughter, Caroline—grow deeper. So when Hollis hears about something called a “Five-Star Weekend”—one woman organizes a trip for her best friend from each phase of her life: her teenage years, her twenties, her thirties, and midlife—she decides to host her own Five-Star Weekend on Nantucket.

Meredith Martin Delinn just lost everything: Her friends, her homes, her social standing - because her husband Freddy cheated rich investors out of billions of dollars. Desperate and facing homelessness, Meredith receives a call from her old best friend, Constance Flute. Connie's had recent worries of her own, and the two depart for a summer on Nantucket in an attempt to heal. But the island can't offer complete escape, and they're plagued by new and old troubles alike.

In the summer of 1951, Miranda Schuyler arrives on elite, secretive Winthrop Island as a schoolgirl from the margins of high society. When her beautiful mother marries Hugh Fisher, Miranda’s catapulted into a heady new world of pedigrees and cocktails. Isobel Fisher, Miranda’s new stepsister is eager to draw Miranda into the arcane customs of Winthrop society. But there are really two clans: the summer families with their steadfast ways and quiet obsessions, and the working class of Portuguese fishermen and domestic workers. Then Miranda is caught in a catastrophe and banished....

After uprooting her life in the States, Irene Steele has just settled in at the villa on St. John where her husband Russ had been living a double life. But a visit from the FBI shakes her foundations, and Irene once again learns just how little she knew about the man she loved. With help from their friends, Irene and her sons set up their lives while evidence mounts that the helicopter crash that killed Russ may not have been an accident.

Every day without fail, Travis Devine puts on a cheap suit, grabs his faux-leather briefcase, and boards the 6:20 commuter train to Manhattan, where he works as an entry-level analyst at the city’s most prestigious investment firm. In the mornings, he gazes out the train window at the lavish homes of the uberwealthy, dreaming about joining their ranks. In the evenings, he listens to the fiscal news on his phone, already preparing for the next grueling day in the cutthroat realm of finance. Then one morning Devine’s tedious routine is shattered by an anonymous email: She is dead.

Meet Jessica Jones: retired superhero, private investigator, loner. She tried her best to be a shiny spandex crimefighter, but that life only led to unspeakable trauma. Now she avoids that world altogether and works on surviving day-to-day in Hell’s Kitchen, New York. The morning a distraught mother comes into her office, Jessica would prefer to nurse her hangover and try to forget last night’s poor choices. But something about Amber Randall’s story strikes a chord with her. Amber is adamant that something happened to her teenage twins while they were visiting their father in the UK.

The year 1996 was the one that changed everything for Maggie Dawes. Sent away at 16 to live with an aunt she barely knew in Ocracoke, a remote village on North Carolina’s Outer Banks, she could think only of the friends and family she left behind...until she met Bryce Trickett, one of the few teenagers on the island. Handsome, genuine, and newly admitted to West Point, Bryce showed her how much there was to love about the wind-swept beach town - and introduced her to photography, a passion that would define the rest of her life. By 2019, Maggie is a renowned travel photographer.

Anna McNichol knows how to take charge. Raised by a single mother, she’s worked to ensure her three children have every advantage she didn’t. And while her marriage has its problems, she values commitment and believes in "till death do us part." Now an empty nester, she’s at the peak of her career and ready to seize the opportunity to focus on her future.