It's been 19 years since ten-year-old Laurel was given a life sentence and six-year-old Rosie was given a new identity. The sisters were the very picture of innocence: two little girls who loved to listen to their mother's bedtime stories and play make-believe in the garden. But then an act of unparalleled horror tears their family apart, leaving Laurel behind bars. Neither sister has laid eyes on the other since then, during which time their lives have followed very different paths.

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.

It is midnight on the morning of Halloween, and Jen anxiously waits up for her 18-year-old son, Todd, to return home. But worries about his broken curfew transform into something much more dangerous when Todd finally emerges from the darkness. As Jen watches through the window, she sees her funny, seemingly happy teenage son stab a total stranger.

At 39, Manon Bradshaw is a devoted and respected member of the Cambridgeshire police force, and though she loves her job, what she longs for is a personal life. Single and distant from her family, she wants a husband and children of her own. One night, after yet another disastrous Internet date, she turns on her police radio to help herself fall asleep - and receives an alert that sends her to a puzzling crime scene.

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.

Everyone has secrets, and Rachel Holloway is no exception. She’s worked hard to keep the past where it belongs: dead and buried. And so far, she’s been very successful. But now the small newspaper where she works wants to produce a podcast on a cold case: the disappearance 12 years ago of young Molly Forster. Some secrets should never see the light of day, and, as far as Rachel is concerned, whatever happened to little Molly is one of them.

After getting a note demanding his presence, Federal Agent Aaron Falk arrives in his hometown for the first time in decades to attend the funeral of his best friend, Luke. Twenty years ago when Falk was accused of murder, Luke was his alibi. Falk and his father fled under a cloud of suspicion, saved from prosecution only because of Luke’s steadfast claim that the boys had been together at the time of the crime. But now, more than one person knows they didn’t tell the truth back then, and Luke is dead.

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.

You think you know the truth about the people you love. But one discovery can change everything.... Eight-year-old Billy goes missing one day, out flying his kite with his sister Rose. Two days later he is found dead. Sixteen years on, Rose still blames herself for Billy's death. How could she have failed to protect her little brother? Rose has never fully recovered from the trauma, and one of the few people she trusts is her neighbour Ronnie, who she has known all her life.

When a woman's body is discovered in a cathedral and hours later a young man is found hanging from a tree outside his home, Detective Lottie Parker is called in to lead the investigation. Both bodies have the same distinctive tattoo clumsily inscribed on their legs. It's clear the pair are connected, but how? The trail leads Lottie to St Angela's, a former children's home, with a dark connection to her own family history. Suddenly the case just got personal.

Dear Elizabeth, I've been watching you. I hope to see you...soon. Liz Cafferky is on the up. Rescued from her dark past by the owner of a drop-in centre for older men, Liz soon finds herself as the charity's face - and the unwilling darling of the Dublin media. Amidst her claustrophobic fame, Liz barely notices a letter from a new fan. But then one of the centre's clients is brutally murdered, and Elizabeth receives another, more sinister note. Running from her own ghosts, Liz is too scared to go to the police.

A teacher goes missing under suspicious circumstances and a man is murdered at a local reservoir. For Detective Robyn Carter, there's no obvious link between the cases. But as she starts to delve into them, her investigations lead her to Abigail, perfect wife and mother to beautiful little Izzy. What was Abigail's connection to the victims? And why is she receiving threatening messages from an anonymous number?

Lauren has spent years running away from her home town, her childhood, and the memories of her best friend, Hannah. Until the 10th anniversary of Hannah’s death forces her to return home and to the group of friends she abandoned there. It should be a quick visit, just so Lauren can pay her respects. At home, Lauren finds Hannah’s old diary. A diary full of secrets. The terrible things Lauren did, the lies she’s told, the reason she ran away. And she receives a message: "I don’t know why you’re back, but I know why you left." Hannah’s dead, isn’t she?

In a town full of liars, who can you trust? When Detective Finnegan Beck is demoted from his high-powered job in Dublin and relocated in disgrace to the small Irish town of Cross Beg, he predicts boredom will be his biggest threat. But then a beautiful local teenage girl is found strangled in the cold, dark woods a mile from town. The prime suspect is the seemingly gentle drifter who found Tanya’s body. Beck seems to be the only person who can’t escape the feeling that Tanya wasn’t killed at random.

This is a fact: Ryan Summers walked into Three Rivers College and killed 13 women, then himself. But no one can say why. The question is one that cries out to be answered - by Ryan's mother, Moira; by Ishbel, the mother of Abigail, the first victim; and by DI Helen Birch, put in charge of the case on her first day at her new job. But as the tabloids and the media swarm, as the families' secrets come out, as the world searches for someone to blame...the truth seems to vanish.