1868, Morpeth. Theodora Breckenridge, still in mourning after the loss of her parents and brother at sea, is more interested in working quietly on her art at the family’s country estate than she is in finding a husband in Sydney society, even if her elder sister Florence has other ideas. Theodora seeks to emulate prestigious nature illustrators, the Scott sisters, who lived nearby. She cannot believe her luck when she discovers a butterfly never before seen in Australia.

When the new deputy librarian, Juliet Lansdown, finds that Bethnal Green Library isn’t the bustling hub she is expecting, she becomes determined to breathe life back into it. But can she show the men in charge that a woman is up to the task of running the library, especially when a confrontation with her past threatens to derail her?

In Nottingham, England, widow Emma Taylor finds herself in desperate need of a job. She and her beloved daughter Olivia have always managed just fine on their own, but with the legal restrictions prohibiting widows with children from most employment opportunities, she’s left with only one option: persuading the manageress at Boots’ Booklover’s Library to take a chance on her with a job.

Sophie Whalen is a young Irish immigrant so desperate to get out of a New York tenement that she answers a mail-order bride ad and agrees to marry a man she knows nothing about. San Francisco widower Martin Hocking proves to be as aloof as he is mesmerizingly handsome. Sophie quickly develops deep affection for Kat, Martin's silent five-year-old daughter, but Martin's odd behavior leaves her with the uneasy feeling that something about her newfound situation isn't right.

Liverpool, 1935: Raised in a strict Catholic family, Viv Byrne knows what’s expected of her: marry a Catholic man from her working-class neighborhood and have his children. However, when she finds herself pregnant after a fling with Joshua Levinson, a Jewish man with dreams of becoming a famous jazz musician, Viv knows that a swift wedding is the only answer. Her only solace is that marrying Joshua will mean escaping her strict mother’s scrutiny. But when Joshua makes a life-changing choice on their wedding day, Viv is forced once again into the arms of her disapproving family.