Although she doesn't quite fit the profile a Booker tragic hero, Miss Emily has often been thought of as a very special tragic case. We think that applying Booker to her presents an interesting perspective on her story. That said, in this stage Emily finds an object of desire, as Booker says. In Homer Barron, Emily sees the chance to have what her father kept from her while he was alive: a romantic relationship, love, marriage, and happiness. Since nobody for miles around would stoop to a relationship with Emily who at "over thirty" (3.6) was considered beyond marriageable age, and since her father had run off any potential suitors, she had to pick somebody from out of town.
For a while it looks like Emily's dream is coming true. She's spitting in the face of tradition by hanging out with a man who is considered socially beneath her, and who her father undoubtedly would not have approved of. She rides around with Homer in the buggy, not caring what anyone thinks.
For the tragic hero in this stage, things start to go wrong. In this case, the town is vicious and interfering, and will not let Emily have her little bit of happiness. On top of gossiping about Emily, they first force the minister on her, and then write to her Alabama cousins, who are brought in to destroy Emily's relationship with Homer. As Booker says, this kind of frustrating situation sometimes leads the hero to commit dark deeds…
The nightmare stage is one of the most confusing in this story. We don't know if Homer and Emily ever agreed to marry. We do know she bought both the arsenic and the men's items while the cousins were with her, and that she was seen with Homer during that period. We don't know why he came to her house that final time, or why she didn't let him leave. Most critics, including Faulkner himself, believe Homer wasn't a good guy; it seems he might have come back to Emily one last time before dumping her. She managed to get the arsenic in him somehow or other.
This is where things really diverge from Booker's tragedy plot structure. For one thing, this stage happens some 40 years before the story ends. In this stage, the tragic hero is supposed to die as a result of her own folly. Emily dies at seventy-four of what appears to be all natural causes. Yet, in some ways she was destroyed when she killed Homer Barron. The last thread of normalcy was permanently severed in that moment. Even though she was able to give painting lessons for almost a decade after the murder, eventually, when the town no longer trusted her with their children, and she made a complete withdrawal into her home. Other than whatever interactions she had with Tobe she was entirely cut off from the rest of the human race.