Katie, the 14-year-old daughter of a travelling family, is left in charge of an ailing mother and her nine brothers and sisters in Dublin whilst her father is in England seeking his fortune.

A member of British Intelligence assumes a fictitious criminal identity and allows himself to be caught, imprisoned, and freed in order to infiltrate a spy organization and expose a traitor; only, someone finds him out and exposes him to the gang...

In Dublin circa 1911, John Cassidy (Rod Taylor), an impoverished idealist, whose ambitions are restricted by the demands of looking after his family, journeys through the social injustices of Dublin life, involving himself with the rowdy tramway-men strike, dawdling with prostitute Daisy Battles (Julie Christie), and seeking a better life. He falls in love with bookshop assistant Nora (Dame Maggie Smith) who encourages him toward a life of writing. Finding success at the Abbey Theatre, his unorthodox views estrange him from family, friends, and his own past.

Thomas Crimmins is a new warder, or guard, in an Irish prison. He is young, naive, and idealistic, determined to serve his country by his part in meting out justice to criminals. His superior, Regan, however, realizes that even prisoners are human beings, and Regan is sick of the eye-for-an-eye attitude that leads the state to execute condemned men, or "quare fellows." Crimmins begins to see that not all is black and white in his new world, and when he becomes involved with Kathleen, the wife of one of the condemned men, his attitude begins to change. When new evidence arises to suggest that Kathleen's husband may not deserve his fate, Crimmins is torn between his duty and his humanity.