For 15 years, Lexi and Jake have played the same six numbers with their friends. Over drinks, dinner parties, and summer barbecues, the three couples have discussed the important stuff - kids, marriages, careers - and they’ve laughed off their disappointment when they failed to win anything. But then, the unthinkable happens. There’s a rift in the group. Someone is caught in a lie. And soon after, six numbers come up that change everything forever.

Ten years ago he killed my son. Today I married him. Ten years ago my darling son Jesse was murdered and our perfect family was destroyed. My strong, handsome boy, so full of life, became a memory, a photo I carried with me everywhere. But today I’m finally close to finding happiness again. My ash-blonde hair has been curled into ringlets. Carefully placed white flowers frame my delicate features. The small, drab chapel has been prettied up with white satin, and there are tiny red hearts scattered on the small table where I will soon sign the register with my new husband. 

Emily and Jake are the perfect couple. Or so everyone says. But Emily just read a letter that has shattered her perfect world. Now she only has one thing on her mind. Which one of her friends is sleeping with her husband?

Gen is on the verge of a divorce from her cheating husband. When her sister, Meg, has a convention to attend in the Big Apple, she invites Gen along to celebrate her newly found freedom. But the perfect sisters’ getaway quickly goes awry when a tipsy Gen defiantly throws her wedding ring off the hotel room’s balcony. Then, wanting some fresh air, she decides to take a late-evening walk alone and vanishes without a trace.

I nearly threw the letter about the inheritance away with the recycling. Late for work, worrying about how I would afford new school shoes for Kate, I just assumed it was a mistake. But perhaps moving to a new home in a quiet seaside town would be the fresh start we both need. Away from the school bullies making Kate’s life a misery, and out of the clutches of my dangerous ex. 

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....

No relationship is perfect. But since the birth of baby Mabel seven months ago, Amber and George have been in desperate need of a night away. Mabel is all that Amber has ever wanted, but she can’t deny that sometimes she struggles to cope. George has booked them into a luxury hotel, and Amber’s sister is babysitting. Yet just as they are ready to leave, Amber can’t suppress a feeling of worry.... 

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.

Hannah has done everything to make sure her life is safe and secure. A long way from her unstable childhood growing up in foster care, she’s content with her sweet, little, messy apartment and her satisfying job as a social worker. She quietly worries that, aged 36, she might never fall in love. But otherwise her life is where she wants it to be. Until, encouraged by her best friend to join a dating app, she meets Alex. He’s irresistibly handsome. He loves the same music as her. The same food as well. 

Tucking her little boy Ollie into bed one night, Sarah notices his beloved teddy bear, which she bought him when he was born, is missing and in its place is a new toy given to him by her ex-husband’s new girlfriend, Laura. When she asks Ollie about it, he begins to shift uncomfortably before whispering, "Laura told me a big secret, and she said I can never tell you." Soon, Ollie is asking to spend more time with his dad and Laura, and shrinking away from Sarah. Then, when she calls to him in the garden one day, Ollie doesn’t answer back. 

Ava only left her daughter in the pushchair for five minutes. The buckle was fastened, and she was sure it was safe. But when she came downstairs, the door was open and Abi was gone - she walked down the road, past the Lovegoods' house, and was never seen again. A year later, the Lovegoods throw a housewarming party, showing off the results of their renovation. Ava doesn’t want to go. She can’t bear to look down that end of the road, to see the place where Abi vanished, and she doesn’t want to spend time with people who don’t share her grief. 

Leah’s perfect marriage isn’t what it seems, but the biggest lie of all is that she’s learned to live with what happened all those years ago. Marie drinks a bit too much to help her forget. And Carly has never forgiven herself for not keeping them safe. 

You're not who you say you are. Neither is she. She thinks she knows me. She believes my marriage is falling apart at the seams, that my husband can barely look me in the eyes. She thinks I’m desperate for a baby, that my longing for a family keeps me up at night. As much as I hate to admit it, all of this is true. She thinks I listen to her advice, that I care about her opinion. That couldn’t be further from the truth. Because she has no idea who I am. She has no clue that I know everything. I know her secret. I know that she did the unforgivable. I know how many lives she ruined.

Alison is lucky, and she knows it. She has the life she always craved, including a happy home with Jeff and their brilliant, vivacious teenage daughter, Katherine - the absolute centre of Alison's world. Then a knock at the door ends life as they know it. Fifteen years ago someone else took Alison's baby from the hospital. And now Alison is facing the unthinkable. Her daughter belongs to someone else. What would you do if you discovered your beloved child is not yours?

Just four words were printed in the card. He doesn’t love you. I’ve been dreaming about this day - marrying Adam, my childhood sweetheart, who I’ve loved for 18 years. I didn’t realize the perfect day would turn into the perfect nightmare. I was so excited to send out the wedding invitations, carefully writing everyone’s names on thick cream paper in beautiful cursive script. I had no idea I was inviting someone to destroy our marriage.