When Mrs. Lyons discovers their friendship, she forces the Johnstone family to move away to the countryside, temporarily separating the twins. However, fate intervenes again as young adults, reuniting Mickey and Eddie. Despite their different social stations, their bond reignites instantly. Eddie, now a university student, tries to help Mickey, who is trapped in dead-end factory work.

Set in Liverpool, England, between the 1950s and 1970s, the story follows the parallel lives of twin brothers, Mickey and Eddie, who are separated at birth. Their destitute mother, Mrs. Johnstone, a working-class woman abandoned by her husband, already struggles to feed her large family. When she discovers she is pregnant with twins, she despairs. Her employer, the wealthy but infertile Mrs. Lyons, manipulates Mrs. Johnstone into giving her one of the babies.

When Mickey discovers the truth, his world implodes. The loving, cheerful boy from the opening scenes is now a paranoid, bitter man wielding a gun. The play races toward its devastating climax as Mickey confronts Eddie, accusing him of taking everything from him, just as Mrs. Lyons’s prophecy looms.