Liverpool, 1855. Ada Houston is alone. Her grandfather has recently passed away, and her brother is missing, last seen working on the Liverpool docks. Everyone assumes him to be dead. But she will not give up hope. Ada's determined search takes her to the Crimea, where she joins the team of Florence Nightingale's nurses. She may have set off looking for her brother, but along the way Ada finds friends, romance and a new purpose in her own life in the most troubling and difficult of places.

Liverpool, 1868. Shrouded in secrecy, Alice Sampson gives birth to a beautiful baby girl. But the former nurse's happiness is blighted by the knowledge that as a penniless, unwed mother, her future, and that of her child, can only be one of shame and disgrace. Then a knock at the door brings a miracle: she is invited to return to the Liverpool Royal Infirmary and her beloved ward. With the help of her friends and the welcome attentions of Reverend Seed, the hospital Chaplain, Alice slowly starts to rebuild her life.

1914. Evie Munro is a Scottish fisher girl, working the herring season from Wick to Great Yarmouth. For Evie, every day is the same - gutting fish at the docks, shoulder-to-shoulder with her friends, followed by fresh bread, a warm whiskey toddy and an early night. But when Germany declares war, everything changes. As her village begins to empty of young men, Evie's life is marked by a heartbreaking tragedy. Her happiness destroyed, she vows to join the war effort as an army nurse, caring for wounded soldiers on the imposing hospital ship Britannic.

1940. Cora Mayhew came to Paris to search for her birth mother and stayed to work for the resistance movement. When Cora's train is struck by Nazi bombs, the only thoughts on her mind as she staggers from the wreckage are to escape to return to her family, and to post the heart-wrenching letter clutched in her hand. Then a German soldier finds and saves Cora. Max Heller is nothing like she would have expected: kind, good-humoured and selfless. Cora can't help falling in love with him as he helps to plot her escape.

1918, London. Twenty-year-old Emily Burdon has been training as a nurse at St. Marylebone Infirmary, learning on the job as she tends to patients from the crowded poorhouses that ring the hospital as well as wounded soldiers returning from the war. She pours her heart into her nursing while she waits for happier times - peace in Europe and the return of her childhood sweetheart, Lewis, from the Western Front. But when the deadly Spanish Flu arrives in London on the heels of the war, Emily’s faith and courage are put to the test.

Following a humiliating experience involving the man she thought she’d marry, Iris Tredwick signs up to the Wrens in order to escape and - hopefully - find ‘the right sort’ of man to please her mother. After a bumpy start, Iris manages to befriend outspoken Mary and dreamer Sally as they are sent to their first posting - in Orkney. There she meets engineer Rob, whose flirtatious nature both charms and confounds straight-laced Iris. Much more appropriate for her is local doctor Stewart, if only she felt the same spark for him as she does for Rob.

Lady Joanna Harcourt and her daughter, Sarah, discover their life of luxury at Goodwill House is over. Because with Lord Harcourt away fighting, the Harcourt girls are facing financial ruin. Lady Joanna is terrified of losing their home, but for Sarah, this means her dreams of becoming a doctor are over. Headstrong Sarah isn’t one to quit! War or not, she’s determined to find a way to save her home and follow her dreams - whatever it takes.

Jane Hadley has nothing to lose when she runs away to join the Women's Auxiliary Air Force. Whatever faces her in war-torn London can't be any worse than staying at home with her abusive father. The city is nothing like she could have imagined, but she's soon on the move, travelling from base to base for her top-secret training. Making plenty of friends along the way, it doesn't take long for Jane to embrace her growing confidence - especially under the attentive eye of dashing Officer Oscar Stanton.

1941. The Blitz rages over London. And even in Cornwall, the war is being fought. When Violet loses her sister in the Blitz, she must take her nieces to safety in Cornwall. On the coast, she meets carefree chorus girl Eva, who is also running from the dangers of London. But Porthcurno hides a secret military base, and soon Violet and Eva realise there’s a battle to fight in Cornwall, too. Together with local Hazel, who works on the base, they must come together to help the war effort. But will their friendship be enough to keep them safe?

Clara Newton is the new Housemother of Shilling Grange Orphanage. Many of the children have been bombed out of their homes and left without families, their lives torn apart by the war, just like Clara’s. Devastated by the loss of her fiancé, a brave American pilot, she is just looking for a place to start again. But the orphans are in desperate need of her help.

Liverpool, 1939. Bella Rogers thought her life was just starting; she can’t wait to get married to her childhood sweetheart, Bobby. But when war is declared and Bobby is called up, his letters stop, leaving Bella heartbroken and alone. Then her family is torn apart by tragedy when her angelic 5-year-old sister dies from a terrible illness. They can barely afford a funeral, but the church is packed with the entire community, devastated for their loss. Grieving for her sister and lost love, Bella finds a job at the Bryant and May factory, making matches.

London 1940. As the war rages in Europe, Rose Brown steps on board a ship bound for America, hoping to escape the danger. She's frightened, but her widowed mammy and three sisters in Ireland need the money she earns as nanny to the rich Townsend family. But while Rose plays with baby Sarah in the salty spray on deck, disaster strikes, and the ocean liner begins to sink. In the chaos, Rose and the baby are separated from the family.

1904: Ellen Copley is still a child when she leaves behind the sooty rail yards of Glasgow and crosses the Atlantic Ocean with a heart full of dreams. Yet within weeks of their arrival in America, her father has disappeared - leaving Ellen with resentful relatives, feeling alone and scared for her future. But then her kind Aunt Rose invites Ellen to stay with her large family in their rambling house on beautiful Amherst Island, which nestles like a jewel in the blue waters of Lake Ontario.

Bristol, 1939. School leaver Maisie Miles suspects her father, a small-time crook, has an ulterior motive for insisting she gets a job at the W. D. & H. O. Wills tobacco factory but keeps it to herself. She's befriended by effervescent Phyllis Mason and kind-hearted Bridget Milligan who take pity on her and take Maisie under their wing. But beneath their happy-go-lucky exteriors, they all harbour dreams and worries about what the future holds.

Alice Lake has arrived in London from Liverpool to start her training as a District Nurse, but her journey has been far from easy. Her parents think that she should settle down and get married, but she has already had her heart broken once and isn’t about to make the same mistake again. Alice and her best friend, Edith, are based in the East End, but before they’ve even got their smart new uniforms on, war breaks out, and Hitler’s bombs are raining down on London.