Lydia, Dean, and Robyn live very different lives, but each of them, independently, has always felt that something was missing. What they don't know is that a letter is about to arrive that will turn their lives upside down. It's a letter containing a secret - one that will bind them together and show them what love and family and friendship really mean.

Sisters. Strangers. Survivors. More than 20 years ago, Claire and Lydia's teenaged sister Julia vanished without a trace. The two women have not spoken since, and now their lives could not be more different. Claire is the glamorous trophy wife of an Atlanta millionaire. Lydia, a single mother, dates an ex-con and struggles to make ends meet. But neither has recovered from the horror and heartbreak of their shared loss—a devastating wound that's cruelly ripped open when Claire's husband is killed.

Shy and gawky, Ana has always daydreamed about living the life of her exotic half-sister Bee, a pop singer who had a number one hit single before she inexplicably vanished from the celebrity scene. When Bee turns up dead, Ana is dispatched to the big city to clear out her apartment. Instantly seduced by the second-hand glamour of Bee's baubles, bangles, and bottles of Pierre-Jouet, Ana takes up with Bee's wild club-hopping cronies.

When she was 9 years old, Melody Browne's house burned down, and it took all of her childhood memories with it. Now she's a single mother of a teenage boy living in Central London. She hasn't seen her parents since she left home at 15, but she doesn't mind. She's better off on her own. She works as a dinner lady at her son's school and has no idea where her humdrum life is heading. But one summer's night, a hypnotist inadvertently unlocks memories of her childhood, and her whole life is turned upside down.

In a windswept British seaside town, single mum Alice Lake finds a man sitting on the beach outside her house. He has no name and no idea how he got there. Against her better judgment, she invites him inside. Meanwhile, in a suburb of London, 21-year-old Lily Monrose has been married for only three weeks. When her husband fails to come home from work one night, she is left alone in a place where she knows no one and with the police telling her that her husband never existed.

Sydney Green is Brooklyn born and raised, but her beloved neighborhood seems to change every time she blinks. Condos are sprouting like weeds, FOR SALE signs are popping up overnight, and the neighbors she’s known all her life are disappearing. To hold onto her community’s past and present, Sydney channels her frustration into a walking tour and finds an unlikely and unwanted assistant in one of the new arrivals to the block - her neighbor, Theo. But Sydney and Theo’s deep dive into history quickly becomes a dizzying descent into paranoia and fear.

True crime writer Wylie Lark doesn’t mind being snowed in at the isolated farmhouse where she’s retreated to write her new book. A cozy fire, complete silence. It would be perfect, if not for the fact that decades earlier, at this very house, two people were murdered in cold blood and a girl disappeared without a trace.

On a beautiful summer night in a charming English suburb, a young woman and her boyfriend disappear after partying at the massive country estate of a new college friend. One year later, a writer moves into a cottage on the edge of the woods that border the same estate. Known locally as the Dark Place, the dense forest is the writer’s favorite place for long walks and it’s on one such walk that she stumbles upon a mysterious note that simply reads, “DIG HERE.”

Melville Heights is one of the nicest neighborhoods in Bristol, England. It’s the sort of place where doctors and lawyers and old-money academics live. It’s not the sort of place where people get stabbed in the back 30 times with a kitchen knife in their own homes. Someone must have seen something. Newlywed Joey Mullen, for example, recently returned from four years of working in Ibiza. She and her husband, Alfie, are eager to find a place of their own in her hometown. But Joey finds herself distracted by the man next door, Tom Fitzwilliam.

A girl with a secret. Longbill Beach, 1982. Emily Vaughn gets ready for the prom. For an athlete, who is smart, pretty and well-liked, this night that should be the highlight of her high school career. But Emily has a secret. And by the end of the evening, that secret will be silenced forever. Forty years later, Emily’s murder remains a mystery. Her tight-knit group of friends closed ranks; her respected, wealthy family retreated inwards; the small town moved on from her grisly attack. But all that’s about to change.

Early one morning on the shore of the Thames, DCI Samuel Owusu is called to the scene of a gruesome discovery. When Owusu sends the evidence for examination, he learns the bones are connected to a cold case that left three people dead on the kitchen floor in a Chelsea mansion thirty years ago. Rachel Rimmer has also received a shock—her husband, Michael, has been found dead in the cellar of his house in France. All signs point to an intruder, and the French police need her to come urgently to answer questions about Michael and his past that she very much doesn’t want to answer.

Owen Pick’s life is falling apart. In his 30s and living in his aunt’s spare bedroom, he has just been suspended from his job as a teacher after accusations of sexual misconduct - accusations he strongly denies. Searching for professional advice online, he is inadvertently sucked into the dark world of incel forums, where he meets a charismatic and mysterious figure. Across the street from Owen lives the Fours family, headed by mom Cate, a physiotherapist, and dad Roan, a child psychologist. But the Fours family have a bad feeling about their neighbor Owen.

Brothers Tony, Sean, and Ned had the perfect upbringing, but now that they are grown-up, real life is starting to get in the way. Tony’s dealing with divorce and a weight problem, novelist Sean is up against a serious case of writer’s block and a shock announcement from his “perfect” new girlfriend, and their parents have a new lodger, Gervase. Why is Bernie, their mother, so keen to give this unsavory waif a home? And what is the real reason for kid brother Ned’s surprise return from his travels in Australia?

At the age of 13, Charlie Quinn's childhood came to an abrupt and devastating end. Two men, with a grudge against her lawyer father, broke into Charlie's home - and after that shocking night, her world was never the same. Now a lawyer herself, Charlie has made it her mission to defend those with no one else to turn to.

Hen and her husband, Lloyd, have settled into a quiet life in a new house outside of Boston, Massachusetts. Hen (short for Henrietta) is an illustrator and works out of a studio nearby and has found the right meds to control her bipolar disorder. Finally, she’s found some stability and peace. But when they meet the neighbors next door, that calm begins to erode as she spots a familiar object displayed on the husband’s office shelf. The sports trophy looks exactly like one that went missing from the home of a young man who was killed two years ago.