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
This is where we get to know all the main characters and the important issues in their lives. We see the scene change from stark, inhospitable, depressing to booming, lush and rich. This act ends with the departures of Carl and Emil, setting the stage for their returns and all the drama that ensues.
Act II
Let the good times roll.
Well, not exactly. Alexandra might have proven herself a successful farmer and landowner, but that doesn't mean her life is free from tragedy. This act includes Marie's increasing dissatisfaction with her marriage, and her brief affair with Emil, which takes place after he returns from Mexico. It concludes when Frank murders them in a confused and fearful rage.
Act III
The final act is all about Alexandra pulling herself back up after Emil's murder and finally learning to live for herself. She pretty much hits rock bottom after she visits Frank in prison, when she starts to feel like a prisoner herself in her own life.
But then, Carl comes back to Hanover. They decide to get married and go off to Alaska. Even after all the tragedy, Alexandra realizes what a profound connection she still has to the Divide. She's determined to come back and live out the rest of her life there.