Ireland, 1939. Father Damian, the principal of St. Jude's Reformatory School appoints Franklin, former soldier with the International brigade in the Spanish Civil War, to the school as the only lay teacher, although the Bishop and most of the other Brothers are against it. Franklin's teaching methods are diametrically opposed to the Brothers'. While the latter headed by Brother John, the prefect, revert to verbal and physical abuse, Franklin tries to build up a relationship based on trust with the boys, discovers their hidden talents and teaches them to read and appreciate poetry. Mercier, an exceptionally talented boy helps him with this task. Intercut with the development of Franklin's relationship with the boys is a series of flashbacks of Franklin's involvement in the Spanish Civil War, where he falls in love with Rosa who gets killed as a war prisoner. On Christmas day, Brother John organises the beating of two boys who are brothers, who have broken a rule of the school. With Franklin's help Mercier prevents this violence. Some weeks into the New Year, Brother John, intent on finding out why Franklin has decided to come and teach at St. Jude's (he believes Franklin to have a Communist agenda), beats Mercier to death. The story ends with Franklin believing that after Mercier's death, if he were to stay on as a teacher at St. Jude's, he would be an accomplice to Mercier's murder. He resigns, intent on joining the English troops in WWII. But as he stands in the school yard one of the boys who had a learning disability recites a poem that Franklin taught him. The boy then runs to Franklin and hugs him Franklin knows he can never leave St. Jude's.
