Have you ever been to a party…and deeply regretted it? Caitlyn and her nine hens arrive in Dublin for a never-to-be-forgotten weekend. As the drink flows and the laughter echoes, her attendees put aside their buried resentments and secret dark agendas. But one of these disturbing agendas will be executed - no matter what. Ten are about to become nine. Who will be the one?

Ed and Kerry Huntington-Barnes have an idyllic life, with their 5-year-old twins, successful careers, a luxurious house and an affluent lifestyle. Yet the secrets they’re harboring force their separation. Kerry is fighting her own demons, amongst which is the knowledge that she is the wrong gender for her husband to ever truly love her. Parallel to this it the death of a local man, Russell Lawson, which affects both Ed and Kerry in different ways. 

When Loren meets Jack, she’s sure he’s the man she’s been waiting for - a perfect husband and father for her young daughter. Shortly after their wedding, their plans to start a life together are put on hold when the couple receives word that Jack’s father has died. In an effort to appease her new husband, Loren invites her mother-in-law, Coralee, to stay with them while she grieves. When strange things begin to occur just after her arrival, Loren questions how much she knows about the woman she invited into her home.

Fiona keeps herself to herself - it is safer that way. She allows few people to get close, having learned the hard way that most have their own agendas. Lowering her barriers and trusting her husband Rob is a decision she has reason to regret. His indiscretions were coming to light even before the news of his hit and run killing one summer afternoon.

After escaping an unhappy marriage, Anna had the rest of her life to look forward to. However, she soon swapped one toxic family situation for another. When she plunged to her death from the bannister to the foot of her staircase whilst painting, initial grief swiftly became speculation. Jamie has minimal support as he mourns his mother. Struggling with his estranged father’s indifference and demands from the stepfamily Anna has thrust on him, he initially turns his loss and anger inward.

Clare and Lorraine have been friends since college and trust each other with their lives. So when Lorraine, a single mother, needs a much-needed night away without her children, she calls on Clare and her husband, Sam, to look after them. They're godparents - what could go wrong? While Clare and Sam believe the children to be asleep, the unimaginable happens and Clare finds baby Theo lifeless in his room. The police are called. Statements are taken. But the biggest nightmare for any parent is about to spiral out of control. Because a lie has been told. An enormous and terrible one. 

Erin lives an idyllic life by the seaside with her baby boy and handsome Australian fiancé. She's upbeat and happy - a natural mum. At least that's what her thousands of followers on Instagram think. In the real world, Erin is struggling with anxiety and finding it difficult to connect with her screaming son. So when a famous agent offers to make her the biggest instamum out there, she's over the moon. 

I only try on one of Nina’s pristine white dresses once. Just to see what it’s like. But she soon finds out...and by the time I realize my attic bedroom door only locks from the outside, it’s far too late. But I reassure myself: The Winchesters don’t know who I really am. They don’t know what I’m capable of....

The first time you see them, out for an evening walk on the cliffs, you’ll think they’re the perfect family. You’ll see a wife who looks so happy, strolling peacefully beside her husband in his dark winter coat, holding her daughter’s hand. But you have no idea what’s really happening in their house.... If you come a little closer, you might hear the way the man speaks to his wife. You might notice that the woman doesn’t have any close friends. That sometimes her husband doesn’t want her to leave the house.

She bursts into my life like a storm, and nothing is the same again. One by one, I watch as my friends fall under her spell. Only I see that her smiles don’t reach her cold, furious eyes. And when I’m accused of things I didn’t do, when my home is vandalized, I know she’s behind it. But she only lets her mask slip when no one is looking, so if I say anything, I’ll look crazy. So when the baby shower comes around, I’m sitting on a velvet sofa in a posh hotel room, surrounded by balloons. But that afternoon, I finally learn the unbelievable truth. There is no baby....

When I arrive unannounced at my husband's studio in need of a shoulder to cry on after hearing that my best student, Alex, has died, I see a pair of wineglasses drying by the sink, and my deepest fear is confirmed: my husband is having an affair. Most women would fall to their knees in tears and throw him out of the house - but I just can't bring myself to do it. Instead, I go home and cook a healthy dinner for our children, walk the dog, and unload the dishwasher without complaint. I need this marriage to work to protect a terrible secret of my own....

When Freya first met Phil, she thought he was the man of her dreams. He bought her roses every week, booked surprise trips to sun-soaked destinations, and showed her affection like she’d never experienced before. But over time the dream had become a violent nightmare. And now Freya is packing her bags, knowing it’s time she escaped their increasingly broken marriage. But then Freya gets a visit from the police. Phil’s been in a horrific car crash and - as he comes around - it becomes clear that he remembers nothing since their blissful honeymoon two years before.

It hits her: the same strange smell that’s been following her for weeks, and the shadow of an image slides into her mind, but is gone just as quickly. Gripped by an ice-cold fear, in that one terrible moment, she realises: it’s not a dream she’s remembering. It’s something that actually happened. 

The phone rings. What Eva doesn’t realize is that the call will signal the end of what she knows to be true. The end of trusting her family. And the end of everything keeping her safe. The phone call is from a hospital hundreds of miles away. A woman has been admitted with a serious head injury, saying she’s Eva’s older sister. A sister Eva never knew she had. Whose name - Nancy - has never once been mentioned by her parents. It seems impossible. Could the two people who brought Eva up have lied to her for her whole life?

Christine and Jessica cross paths working at the advertising agency Christine runs with her husband. These two women are about to uncover the dark secrets of their own traumatic pasts. But they have no idea that they are connected. The shocking truth of what happened at the wedding all those years ago, and what became of Margaret, is going to blow their lives apart in more ways than each of them could ever have imagined....