For a three-act plot analysis, put on your screenwriter’s hat. Moviemakers know the formula well: at the end of Act One, the main character is drawn in completely to a conflict. During Act Two, she is farthest away from her goals. At the end of Act Three, the story is resolved.
Act I
Blanche arrives in New Orleans, reunites with sister, and meets Stanley. Conflict seems inevitable as we get a glimpse of Stanley’s violent streak, and of course the Mitch saga begins. Stella’s pregnancy is revealed as well.
Act II
Tension rises as Stanley grows more and more frustrated with Blanche’s presence. Her relationship with Mitch is threatened by rumors of her activities in Laurel, and Stanley rapes Blanche.
Act III
Stella decides to send Blanche to a mental institution. Stanley, predictably, plays some more poker.