1950s Liverpool. In the tight-knit Irish Catholic community of the Four Streets, two girls are growing up. One is motherless – and hated by the cold woman who is determined to take her dead mother's place. The other is hiding a dreadful secret which she dare not let slip to anyone, lest it rips the heart out of the community. What can the people of the Four Streets do when a betrayal at the very heart of their world comes to light?