New friends Sam, Margaret and Diana are thrilled to be getting out of the city for a girls’ weekend - they’ve bonded over their messy divorces, and every mile on the odometer feels like another step towards putting their exes in the past. But when car trouble halfway into their trip strands them in the most unlikely of mountain towns, they come face-to-face with the hurts and betrayals they were so desperate to leave behind. When Diana doesn't return home after a night out, Sam and Margaret's search for her reveals just how little they know about their friend.

As children, Sam and Elli were two halves of a perfect whole: gorgeous identical twins whose parents sometimes couldn’t even tell them apart. They fell asleep to the sound of each other’s breath at night, holding hands in the dark. And once Hollywood discovered them, they became B-list child TV stars, often inhabiting the same role. But as adults, their lives have splintered. After leaving acting, Elli reinvented herself as the perfect homemaker: married to a real estate lawyer, living in a house just blocks from the beach.

Half-hidden by forest and overshadowed by threatening peaks, Le Sommet has always been a sinister place. Long plagued by troubling rumors, the former abandoned sanatorium has since been renovated into a five-star minimalist hotel. An imposing, isolated getaway spot high up in the Swiss Alps is the last place Elin Warner wants to be. But Elin's taken time off from her job as a detective, so when her estranged brother, Isaac, and his fiancée, Laure, invite her to celebrate their engagement at the hotel, Elin really has no reason not to accept.

Brecken Hill in upstate New York is an expensive place to live. You have to be rich to have a house there, and Fred and Sheila Merton certainly are rich. But even all their money can't protect them when a killer comes to call. The Mertons are brutally murdered after a fraught Easter dinner with their three adult kids. Who, of course, are devastated.

Lex Gracie doesn't want to think about her family. She doesn't want to think about growing up in her parents' House of Horrors. And she doesn't want to think about her identity as Girl A: the girl who escaped, the eldest sister who freed her older brother and four younger siblings. It's been easy enough to avoid her parents - her father never made it out of the House of Horrors he created, and her mother spent the rest of her life behind bars. But when her mother dies in prison and leaves Lex and her siblings the family home, she can't run from her past any longer.

Daisy and Simon’s marriage isn’t what it seems…. After years together, the arrival of longed-for daughter Millie sealed everything in place. They’re a happy little family of three. So what if Simon drinks a bit too much sometimes — Daisy’s used to it. She knows he’s just letting off steam. Until one night at a party things spiral horribly out of control. And their happy little family of three will never be the same again.

Addison’s about to get married, but she’s not looking forward to the big day. It’s not her fiancé; he’s a wonderful man. It’s because Addison doesn't know who she really is. A few years ago, a kind driver found her bleeding next to a New Jersey highway and rescued her. While her physical wounds healed, Addison’s memory never returned. She doesn’t know her real name. Or how she ended up injured on the side of a road. Or why she can’t shake the notion that she may have done something very, very bad.

Pete Riley answers the door one morning and lets in a parent's worst nightmare. On his doorstep is Miles Lambert, a stranger who breaks the devastating news that Pete's son, Theo, isn't actually his son - he is the Lamberts', switched at birth by an understaffed hospital while their real son was sent home with Miles and his wife, Lucy. For Pete, his partner Maddie, and the little boy they've been raising for the past two years, life will never be the same again.

Grace Holloway keeps to herself. Since narrowly escaping death at the hands of the man who kidnapped her, she’s thrown herself into the small inn she runs in Rock Harbor, Maine. It’s quiet, quaint and, in the off-season, completely isolated—the perfect place for Grace to keep her own secrets. But Grace isn’t the only one with something to hide, and Rock Harbor isn’t just a sleepy vacation town. Someone is taking young women—girls who look an awful lot like Grace did when she was kidnapped so many years ago.

Anna Hart is a seasoned missing persons detective in San Francisco with far too much knowledge of the darkest side of human nature. When tragedy strikes her personal life, Anna, desperate and numb, flees to the Northern California village of Mendocino to grieve. She lived there as a child with her beloved foster parents, and now she believes it might be the only place left for her. Yet the day she arrives, she learns that a local teenage girl has gone missing.