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. 

Kat remembers the days when her only daughter Amy wouldn't leave her side. But now Amy is grown up and gone - to university in a town several hours away. Kat's house - which once felt too full, too noisy, too busy - is deathly quiet, and Kat awaits the daily phone call to tell her that her beloved daughter is thriving and happy. But one day Amy doesn’t call. Kat’s husband and friends think she is being paranoid. But Kat knows right away that something is very wrong.

Marianne has a life others dream of. A beautiful townhouse on the best street in the neighbourhood. Three bright children who are her pride and joy. Sometimes her past still hurts: losing her mother early, growing up in foster care. But her husband, Simon, is always there. A successful surgeon, he’s the envy of every woman they’ve ever met. Flowers, gifts, trips to France: nothing is too good for his family. Then Simon says another woman’s name. The way he lingers on it, Caroline, gives Marianne a shudder of suspicion, but she knows it’s nothing - she can’t entertain this flash of paranoia.

Clare is ready for a break. It's been a tough year and now she wants to put her feet up. Arriving at the Italian villa for their summer holiday, she decides it's high time her husband and his family did some of the work. After all, her husband owes her.... Now her brother-in-law Jamie has brought a wife, someone none of them have met before. Ella is everything Clare isn't. Glamorous. Young. Influential. But she knows a secret about Clare. Something that has the power to break the whole family apart.

They live 500 miles apart. Yet their lives are about to collide. Lissa loves her job as a nurse, but recently she's been doing a better job of looking after other people than looking after herself. After a traumatic incident at work leaves her feeling overwhelmed, she agrees to swap lives with someone in a quiet village in Scotland. Cormac is restless. Just out of the army, he's desperately in need of distraction and there's precious little of it in Kirrinfief. Maybe three months in London is just what he needs.