The play begins with Henry Reyna and his 38th Street Gang members headed to a local dance. While at this dance, they encounter their rivals: The Downey Gang. Henry’s brother, Rudy, sparks a fight between the two gangs. This results in the 38th Street Gang leaving the scene of the party.
Della, Henry’s girlfriend, then accompanies him on a trip to Sleepy Lagoon, a popular hang-out spot for Mexican-American youth. While there, Henry hears noises coming from the Williams’ Ranch, and suspects that there is a party being held there. Henry and Della decide to go to the ranch, which (unbeknownst to them) was just harassed by the Downey Gang.
Mistaking Henry and his friends for the troublesome Downey Gang, the Williams’ attack them. This attack results in the death of Jose Williams, an occupant of the Williams’ ranch. Henry and the 38th Street Gang members are soon arrested and charged for the murder of Jose Williams. Evidence clearly showed that the Downey Gang was responsible for the death of Jose Williams, but the jury was strongly against the 38th Street Gang members. Despite the efforts of George Shearer (their lawyer), and Alice (their editor), the 38th Street Gang members were unfairly sentenced to time in prison.
The boys sat in San Quentin Prison, where they waited for their cases to be appealed. During this time, Henry develops a crush on Alice despite still being involved with his girlfriend Della. George Shearer, their lawyer, is drafted to serve in the war. Henry spent the rest of his sentence in isolation, where his inner voice named Pachuco decides to leave.
While the gang is in jail, Zoot Suit Riots break out all over Los Angeles and neighboring cities. The boys are eventually released from jail. At this time, Henry has three different paths of life, and the audience of the play has the opportunity to choose his fate. In the first path, Henry goes back to jail and dies due to stress. In the second path, Henry serves in the war and dies as a hero serving his country. Finally, in the third path, Henry gets married and has children.