Act I
The musical opens in Liverpool, England during the 1980s. A woman named Mrs. Johnstone stands over the dead bodies of her two sons, Mickey and Eddie. She begins to sing “Tell Me It’s Not True." The narrator says that the story behind this tragic scene began thirty years ago. The play then flashes back to the 1950s.
Mrs. Johnstone is a single mother living in significant debt. She is unable to pay the milkman when he arrives at her door. She takes a job with the Lyons family, working as their maid. She subsequently discovers that she is pregnant with twins, much to her great dismay. She is uncertain about how she will pay for two more children. At the same time, she learns that Mrs. Lyons wants to have a child of her own but is physically unable to get pregnant. Her husband has dissuaded her from adoption, as he does not want a child that is not biologically his. When Mrs. Lyons finds out about Mrs. Johnstone's pregnancy, she asks her for one of the twins, singing "My Child." She says no one will ever have to know what they did.
Initially hesitant, Mrs. Johnstone accepts Mrs. Lyons' offer, hoping that it will give one of her children a better, more financially secure future. Mrs. Johnstone swears on a Bible. After the twins, named Mickey and Eddie, are born, she gives Eddie up to Mrs. Lyons and tells her other children that one of the twins died. She immediately regrets her decision, as she still feels attached to Eddie and takes every opportunity she can to see him at the Lyons' house while she is working. Mrs. Lyons is upset by her behavior and fires her, paying her off with a large severance. She tells her to stay away from the house and make certain that the boys never meet, as she suspects something terrible will happen if they do.
Years later, Mickey and Eddie meet while playing on the street. They take an immediate liking to one another. After learning that they mysteriously share a birthday, they make a pact to be "blood brothers," cutting their hands to seal the agreement. Mickey later shows up at the Lyons' house, hoping to see Eddie. Mrs. Lyons realizes who he is and tells him to leave. Eddie and Mrs. Lyons argue about it. Eddie curses at her and she slaps him. Later, Eddie sneaks out to hang out with Mickey and his friend Linda. They get in trouble with a police officer for throwing rocks. Mrs. Johnstone tells Eddie he is forbidden from seeing Mickey, but gives him a locket with a picture of herself and Mickey (though it is implied it is a picture of her and Eddie) when the Lyons family moves away from Liverpool. Mickey wanders around the neighborhood, aimlessly searching for his friend, who he misses very much. The act ends with the Johnstones also moving to the countryside.
Act II
The Johnstone family also moves to the countryside to try and have a better life. Mickey and Linda continue to spend time together and develop a quiet romance. Neither of them addresses their feelings directly. Eddie and Mickey run into each other one day and happily reunite. They begin spending time together and discuss their newfound curiosity about sex and girls. Mickey invites Eddie to see a pornographic film and, despite his initially scandalized reaction, Eddie agrees.
Mrs. Lyons finds out about this and decides that Mrs. Johnstone has moved back to steal her son back. She confronts Mrs. Johnstone who honestly says she had no idea. After a heated exchange, Mrs. Johnstone turns her back and Mrs. Lyons takes up a kitchen knife and attempts to stab her. Mrs. Johnstone narrowly avoids the attack and fights her off, forcing her out of the house. Mrs. Lyons continues to deteriorate mentally, as described in the song, "Mad Woman on the Hill."
The play skips forward in time once more. The boys are eighteen years old. Mickey has not worked up the courage to be honest with Linda about how he feels. Eddie also has feelings for Linda but doesn't want to hurt Mickey, so he tells Mickey what to say to Linda. Eddie goes off to college while Mickey and Linda begin a romantic relationship. Linda gets pregnant and the two decide to get married. Mickey gets a job at a local factory and moves his family in with his mother. Mickey loses his job during a recession. Eddie returns home from college and is excited to see Mickey, but the two quickly realize they are at very different points in their lives. They fight briefly and decide to go their separate ways.
Increasingly desperate, Mickey is convinced by his older brother Sammy to take part in a robbery for extra money. The robbery goes sideways and Sammy murders someone. Mickey is charged as an accessory to the murder and sentenced to seven years in prison. He becomes incredibly depressed during this time. He is given a prescription for antidepressants and is eventually let out on good behavior.
Mickey struggles to reenter regular society after his release. He becomes addicted to his medication and never wants to see people. Linda tries to help him, to no avail. Eddie, now a local politician, steps in after Linda reaches out, helping Mickey find a job and a place for his whole family. Linda starts spending more and more time with Eddie.
A vengeful Mrs. Lyons sees them together once and points it out to Mickey, saying that they are engaged in an affair, despite her lack of solid evidence, hoping he will snap. Mickey grabs his gun and rushes to the courthouse where Eddie works. When Mickey arrives, Eddie swears he has no designs on Linda. Mrs. Johnstone appears and tells the two men about their secret brotherhood. Bereft and distraught, Mickey flings his hands up, accidentally firing the gun, killing Eddie. The police open fire on Mickey, killing him. Mrs. Johnstone returns to her position from the beginning of the play. The narrator wonders aloud, in a reprise of the final song, "Tell Me It's Not True," whether it was the superstition that killed the two boys or their class divide.
