When Dilly's husband is left unable to work, she has to make an unthinkable decision. With four children already at home, they cannot afford to feed their new-born. The Farthing family, who live at the big house, know how it feels to lose a child. They are going through their own form of horror having just lost their own daughter to measles. Despite their grief, they decide to offer Dilly a lifeline: they'll adopt the child and employ Dilly as their maid. The consequences of this act of desperation will irrevocably change the lives of both families - and the onset of WWI even more so.