When sixteen-year-old Sally is evacuated to the English south coast, she is terrified by what lies ahead of her. All she knows are the sights and sounds of London's East End – but Sally swallows her tears as they leave the familiar landmarks behind, knowing that she has to be a Grown-Up Girl and play mother to her six-year-old brother Ernie. Playing mother is nothing new for Sally – their real mother Florrie, a good-time girl, hasn't even come to the station to wave them off and Ernie, crippled at an early age by polio, is used to depending on his older sister.

In the heart of Dressmakers' Alley, Madame Pauline’s sweatshop is rumoured to be a particularly unpleasant place to work. Filled with seamstresses paid a pittance who turn a blind eye to what darker activities are hidden behind locked doors. Young Winnie Brown is keen to prove her value to the Women Movement and secures a job as a seamstress to investigate the whispers of some unsavoury goings on. Her concerns are soon justified when she hears a desperate cry for help.

Elizabeth Roby lives a content and privileged life in London with husband Jonathon and children, Emily and George. But with the outbreak of war, everything changes. Jonathon informs his family that they have to move from their smart London home to the riverside town of Wivenhoe and their new home Harbour House, where Jonathon will do his duty for his country as part of the Admiralty at the shipyards. But Elizabeth is devastated. How will she start a new life in a place she hardly knows, surrounded by strangers?

Cambridgeshire - March 1939. As the clouds of war begin to gather in Europe, the Talbot family of rural Blackberry Farm will be torn apart, just as so many families all over the world will be. Life will never be the same again. Whilst in London, the Salmons family will feel the pain of parting and loss. Brought together by war, the two families become intertwined and, as the outlook looks bleak, they must draw on each other’s strength to fight through the hard times.

When her family is struck by a terrible tragedy, Sarah Nightingale is forced to go into service at Grey Friars House as an under-nursery-maid. Although the situation wasn’t of her making Sarah thrives there, but life for her younger brother Alfie is not as easy. Desperate to avoid being sent to the workhouse, Alfie runs away to London to seek his fortune. But young and inexperienced with the dangerous streets of London, Alfie is tricked and sold to work as a slave on a coal barge. Sarah misses her brother terribly but knows she must find a way to survive if she ever wants them to be reunited.

Born in the workhouse and adopted by a former suffragette, Frances Brakespeare was encouraged from an early age to be strong, independent and to pursue a career as a doctor. The tragic loss of the love of her life in the Great War propels Frances to commit to her one true vocation. Rebelling against the unfair treatment of female doctors Frances is dismissed from her London post and things continue to take a turn for the worse when Izzy, her benefactress dies and Frances finds herself homeless.

At the heart of Dover's Market Square lies the Castle's Café. A bustling, homely place run by the formidable Nellie Castle and her six children. Since the scandalous birth of her beloved son 10 years before, Marianne, Nellie's eldest daughter, has preferred to stay in the kitchen, hidden away from the town gossips. Overcome with shame, Marianne has never revealed the name of Donny's father - not even to her own mother. But with World War II just around the corner, Marianne's past catches up with her. And suddenly the lives of the Castle family become a lot more complicated.

Robinswood, Co. Waterford, 1939. The once grand house is home to two very different families. Despite delusions of grandeur, Lord and Lady Kenefick and their adult children live a life of decayed opulence as the money needed to keep such a large house and grounds ever dwindles. Meanwhile, the Murphy family, Dermot, Isabella and their three almost grown-up girls, live and work on the estate and do their best to keep everything running smoothly.

As a small child, Nellie Peace was always dreaming but sensed her mother’s rejection. Abandoned and sent into service at Beaumont House at an early age, Nellie is lost and alone until she meets the unpredictable and reclusive artist Lucas Harrington and falls in love with him. This unlikely association between master and servant is encouraged by Lucas’ gentle-natured Aunt Alice, as Lucas sees something unusual in Nellie and is compelled to paint her. Broken promises lead to inevitable heartbreak, and Nellie flees Beaumont House in disgrace for London.

It is 1939, and working-class Evie Bishop has received a scholarship to study mathematics at Oxford when tragedy turns her life upside down. Evie must seek a new future for herself and, inspired to contribute to the war effort, joins the Women’s Auxiliary Air Force as an Ops Room plotter. Posted to a fighter station on the Sussex Coast, Evie befriends two other WAAFs. But the German bombers seem to know more than they should about the base’s operations, and soon Evie, May and Jess are caught up in a world more dangerous than they ever imagined.

As war looms in Europe, 18-year-old Jane Shaw runs the household as an unpaid servant on a meagre budget. When tragedy strikes and she loses her beloved younger brother in suspicious circumstances, Jane takes a position in service looking after Ned, a troubled young boy. Here she meets dashing David Heron, Ned's Uncle and they form an immediate attachment until she is dismissed after being accused of stealing a piece of jewellery. Returning home, Jane and her sister, Melia, are soon orphaned and left at the mercy of their Aunt Alice.

Three very different girls sign up as trainee nurses at a big London teaching hospital in 1934. Dora leaves her overcrowded, squalid working-class home for a better life. But has she got what it takes to keep up with other, better-educated girls? And will her hated stepfather ever let her go? Helen is born for the job; her brother is a doctor, her all-powerful mother a hospital trustee. But will Helen’s secret misery be her downfall? An aristocratic rebel, Millie’s carefree attitude will find her up in front of Matron again and again. Will she ever care enough to make a nurse? Or will she go back to the glamorous life she was born to?

Dottie and Mary forged a friendship over a bag of penny sweets when they were eight years old. They've shared everything together since then. Now, at seventeen, they're both shopgirls working at Woolworths. As they go out in the world in pursuit of love and happiness and life becomes more complicated, the simplicity of their childhood dissolves. The heady excitement of first love will consume them both, but the pain of unintentional betrayal will test their friendship.

Hull, 1940. Widowed Edie Copeland has just arrived on Exchange Street, heavily pregnant and with heavy suitcase in tow. She left York after tragedy struck to make a fresh start, but she's a stranger to this street, and her new landlord doesn't hesitate to remind her of this, widow or not. Luckily, the neighbours are a little more welcoming and Edie is soon made to feel at home by the Maguires and the Scuttles. As air raids sound and the war feels closer than ever, the community has to stick together. But Edie is hiding something, and she doesn't know how much longer her secret is safe.

When Sally, Beth, Margaret and Rachel meet at a job interview for the wonderful new store in Oxford Street, they have no idea they will become lifelong friends. When all four girls are lucky enough to be selected as sales staff their exciting new adventure begins. Join them as they overcome heartbreak and grief, find love and happiness and remain united in their friendship, whatever life throws at them.