Sophie and Rosa Moran are born into a working-class family struggling to rise above poverty. Their father is a lowly employee at Thackreys' Bank, a powerful family-run concern. Sophie and her sister first come into contact with the Thackrey family - especially young Lydia - as children through their father's job. In spite of the social differences between them, they form an enduring friendship.
Years later, their paths cross again when Barney Moran is sacked from the bank, and the girls beg Mr Thackrey for help. Swept up in a dramatic chain of events, the lives of the two families are changed forever . . .