Marian Caldwell is a 36-year-old television producer, living her dream in New York City. With a fulfilling career and satisfying relationship, she has convinced everyone, including herself, that her life is just as she wants it to be. But one night, Marian answers a knock on the door ... only to find Kirby Rose, an 18-year-old girl with a key to a past that Marian thought she had sealed off forever. From the moment Kirby appears on her doorstep, Marian’s perfectly constructed world - and her very identity - will be shaken to its core.

It’s 2 a.m. on a Saturday night in the spring of 2001, and 28-year-old Cecily Gardner sits alone in a dive bar in New York’s East Village, questioning her life. Feeling lonesome and homesick for the Midwest, she wonders if she’ll ever make it as a reporter in the big city - and whether she made a terrible mistake in breaking up with her longtime boyfriend, Matthew. As Cecily reaches for the phone to call him, she hears a guy on the barstool next to her say, “Don’t do it - you’ll regret it.” Something tells her to listen.

Nina Browning is living the good life after marrying into Nashville's elite. More recently, her husband made a fortune selling his tech business, and their adored son has been accepted to Princeton. Yet sometimes the middle-class small-town girl in Nina wonders if she's strayed from the person she once was. Tom Volpe is a single dad working multiple jobs while struggling to raise his headstrong daughter, Lyla. His road has been lonely, long, and hard, but he finally starts to relax after Lyla earns a scholarship to Windsor Academy, Nashville's most prestigious private school.

Growing up, Josie and Meredith Garland shared a loving, if sometimes contentious, relationship. Josie was impulsive, spirited, and outgoing, Meredith hardworking, thoughtful, and reserved. When tragedy strikes, their delicate bond splinters. Fifteen years later, Josie and Meredith are in their late 30s, following very different paths.  

Claudia and Ben are the perfect couple. Ever since their first date, when they both admitted they had no desire for children, their courtship and marriage seemed destined. Their relationship is about freedom, possibility, and exploration. About being together because they want to be together. Not because children are caging them with 18 years of obligation. But then Ben changes his mind: He does want children, after all.

Ellen's relationship to Andy doesn't just seem perfect on the surface; it really is perfect. She loves his family, and everything about him, including that he brings out the best in her. That is, until Ellen unexpectedly runs into Leo. The one who got away. The one who brought out the worst in her. The one she can't forget.

Rachel White is the consummate good girl. A hard-working attorney at a large Manhattan law firm and a diligent maid of honor to her charmed best friend Darcy, Rachel has always played by all the rules. But that changes the night of her thirtieth birthday when Rachel finally confesses her feelings to Darcy's fiancé, and is both horrified and thrilled to discover that he feels the same way. As the wedding date draws near, events spiral out of control, and Rachel knows she must make a choice between her heart and conscience.

Darcy Rhone thought she had it all figured out: the more beautiful the girl, the more charmed her life. Never mind substance. Never mind playing by the rules. Never mind karma. But Darcy's neat, perfect world turns upside down when her best friend, Rachel, the plain-Jane “good girl,” steals her fiancé, while Darcy finds herself completely alone for the first time in her life . . . with a baby on the way. Darcy tries to recover, fleeing to her childhood friend living in London and resorting to her tried-and-true methods for getting what she wants.

When it comes to relationships, 34-year-old Kate Turner is ready to say "Bah, humbug". The sleepy town of Blexford, England, isn't exactly brimming with prospects, and anyway, Kate's found fulfillment in her career as a designer and in her delicious side job baking for her old friend Matt's neighborhood café. But then her best friend signs her up for a dating agency that promises to help singles find love before the holidays. Twenty-three days until Christmas. Twelve dates with 12 different men. The odds must finally be in her favor...right?

They're a glamorous family, the Caseys. Johnny Casey, his two brothers Ed and Liam, their beautiful, talented wives and all their kids spend a lot of time together - birthday parties, anniversary celebrations, weekends away. And they're a happy family. Johnny's wife, Jessie - who has the most money - insists on it. Under the surface, though, conditions are murkier. While some people clash, other people like each other far too much.... Everything stays under control until Ed's wife Cara, gets concussion and can't keep her thoughts to herself.

It was supposed to be the happiest day of her life. Zoe was sitting in her hotel room, in her perfect white dress, looking forward to the moment when she would make kind, handsome Toby her husband. Then, there was a blank. They said she must have fainted, overcome with emotion. But nothing felt quite right afterward. Did something happen in that missing time? 

Becky still adores the traditions of Christmas: Her parents host, carols play on repeat, her mother pretends she made the Christmas pudding, and the neighbors come ’round for sherry in their terrible holiday sweaters. Things are looking cheerier than ever, until Becky’s parents announce they’re moving to ultra-trendy Shoreditch - unable to resist the draw of craft beer and smashed avocados - and ask Becky if she’ll host this year. What could possibly go wrong? 

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.

Bea Schumacher is a devastatingly stylish plus-size fashion blogger who has amazing friends, a devoted family, legions of Insta followers - and a massively broken heart. Like the rest of America, Bea indulges in her weekly obsession: the hit reality show Main Squeeze. The fantasy dates! The kiss-off rejections! The surprising amount of guys named Chad! But Bea is sick and tired of the lack of body diversity on the show. Since when is being a size zero a prerequisite for getting engaged on television? Just when Bea has sworn off dating altogether, she gets an intriguing call.

When Mallory Blessing's son, Link, receives deathbed instructions from his mother to call a number on a slip of paper in her desk drawer, he's not sure what to expect. But he certainly does not expect Jake McCloud to answer. It's the late spring of 2020 and Jake's wife, Ursula DeGournsey, is the frontrunner in the upcoming Presidential election. There must be a mistake, Link thinks. How do Mallory and Jake know each other?