In the spring of 1945 a mother dies, leaving four children to fend for themselves in a Dublin tenement.

Nancy, the oldest, lives in dread of the family being split up. The power to send them all to industrial schools such as Artane and Goldenbridge lies with the 'Cruelty Men'. Their spy, the Pig Farmer, lives next door and holds a long term grudge against the family.

Thankfully Nancy has loyal friends in Summerhill and the Diamond, among them Lilly, her brother Charlie Weaver, a Dublin newsboy, and their ma, Maggie. Through work, Nancy becomes friendly with Karla, a Jewish refugee from Prague.

When Nancy accidentally betrays Charlie to the police, Charlie ends up in Artane industrial school. Desperate to keep her guilty secret and still help her friend, Nancy and Lilly come up with a plan to help Charlie escape on the boat to England. 

Just as her life begins to unravel, Karla steps in with a possible solution to Nancy's problems. Will Nancy succeed in keeping the family together? And at what cost?