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.

Fifteen-year-old Ellie Mack was the perfect daughter. She was beloved by her parents, friends, and teachers. She and her boyfriend made a teenage golden couple. She was days away from an idyllic summer vacation, with her whole life ahead of her. And then she was gone. Now her mother, Laurel Mack, is trying to put her life back together.

Alex Dale is lost. Destructive habits have cost her a marriage and a journalism career. All she has left is her routine: a morning run until her body aches, then a few hours of forgettable work before the past grabs hold and drags her down. Every day is treading water, every night is drowning. Until Alex discovers Amy Stevenson. Amy Stevenson, who was just another girl from a nearby town until the day she was found unconscious after a merciless assault. Amy Stevenson, who has been in a coma for fifteen years, forgotten by the world.

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.

Years after an Easter weekend tragedy devastates a family, they return to the house they grew up in to unearth the many secrets hidden within the nooks and crannies of home.

In the early hours of a summer morning, a young woman steps into the path of an oncoming bus. A tragic accident? Or suicide? At the center of this puzzle is Adrian Wolfe, a successful architect and grief-stricken widower, who, a year after his third wife's death, begins to investigate the cause. As Adrian looks back on their brief but seemingly happy marriage, disturbing secrets begin to surface. The divorces from his two previous wives had been amicable, or so it seemed; his children, all five of them, were resilient as ever, or so he thought.

For Lucy Riddick, Venice has always been the dream destination, the ideal place to lose herself. And now she needs to do just that. The secret she's been keeping has finally caught up with her and Lucy needs to disappear - fast. But what if, when she sets foot in Venice, Lucy finds the one thing she has been running from?

Fifteen-year-old Rosie lies in hospital fighting for her life. She’s trying to tell her mother what happened to her, but she can’t speak the words out loud. Toni is a doting and over-protective mother, terrified for her daughter’s life. Having lost her husband in a tragic accident, Toni has dedicated her life to keeping Rosie safe from harm. She needs to know what secrets Rosie has been keeping and how she ended up in a hospital bed - but Toni has a secret of her own....

In 1986, Eddie and his friends are on the verge of adolescence, spending their days biking in search of adventure. The chalk men are their secret code, stick figures they draw for one another as hidden messages. But one morning, the friends find a chalk man leading them to the woods. They follow the message, only to find the dead body of a teenage girl. In 2016, Eddie is nursing a drinking problem and trying to forget his past, until one day he gets a letter containing a chalk man — the same one he and his friends saw when they found the body.

Miranda's sister Kerri has a new boyfriend. He's a handsome charmer who seems to dote on Kerri. But Brendan isn't the man he says he is. Miranda should know. She broke off her own affair with him just a few weeks ago when she found him reading her diary.

When Jamie and Kirsty move into their first home together, they are full of optimism. The future, in which they plan to get married and start a family, is bright. The other residents of their building seem friendly too, including the Newtons, a married couple who welcome them to the building with open arms. But then strange things start to happen. Dead rats are left on their doorstep. They hear disturbing noises, and much worse, in the night.

Three British couples meet around the pool on their Florida holiday and become fast friends. But on Easter Sunday, the last day of their vacation, tragedy strikes: the 14-year-old daughter of an American vacationer goes missing, and her body is later found floating in the mangroves. When the shocked couples return home to the UK, they remain in contact, and over the course of three increasingly fraught dinner parties they come to know one another better. But they don't always like what they find.

Cat Kinsella overcame a troubled childhood to become a detective constable. When she’s called to the scene of a murder, not far from the pub her estranged father still runs, she discovers that Alice Lapaine is dead. Cat and her team suspect Alice’s husband, until she receives a phone call that links the victim to Maryanne Doyle, a teenage girl who went missing in Ireland 18 years earlier. The call raises uneasy memories for Cat. Though she was only a child, Cat knew that her father wasn’t telling the truth when he denied knowing anything about Maryanne or her disappearance.

Lisa, a single mother, devotes herself to raising her 16-year-old daughter, Ava. She doesn’t speak of her past or Ava’s absent father. Ava is getting tired of her overprotective mother. She wants to live like a normal teenager. As her life begins to unravel, Lisa knows that the only way she can protect herself and her daughter is to face her fears. Yet courage won’t be enough. She’ll need help from the only person she can trust - her best friend, Marilyn. Between them, they have to save Ava, and to do that, they have to be honest with each other.

When Catherine learns that she is dying, she remembers the words her husband once jokingly uttered and decides to leave him the ultimate posthumous gift: a time capsule containing photographs of their life together along with tape recordings in which she recounts every secret she ever kept, every unspoken thought whether loving or treacherous - the things they never said.