NOTE: This spoiler was sent in by Mike B.
Bluesman Son House tells us through archived footage that the worst kind of blues are the blues caused by love.
Rae (Christina Ricci) and Ronnie (Justin Timberlake) have a romp in the sack before Ronnie has to head off to the army. Afterwards his nerves cause him to throw up while Rae soothes him. Rae has a chronic cough, but is hesitant to go to the grocery store to pick up medicine. Ronnie gives Rae a watch identical to his. Every night the two watches will beep at the same time and they'll think of each other. Gill picks up Ronnie in his pickup truck and they head off leaving Rae crying on the lawn. Rae's hunger for sex starts almost immediately and she writhes on the ground like she's possessed.
Reverend R.L. is trying to calm down Lazarus (Samuel L. Jackson). Lazarus goes inside a small cafe and sits with his wife. She's leaving him for his younger brother because living with Laz makes her feel old.
Rae meets up with the local drug dealer Tehronne to quench her hunger for deep....well...not conversation. She apparently meets him for sex every time Ronnie heads out of town. Rae leaves and still persistently coughing, goes towards the grocery store where it turns out her mom works. She and her mom have a very tenuous relationship.
Lazarus goes home and mows down all of his wife's roses with his tractor.
That night Rae goes to a party and gets drunk and stoned to ease her depression over Ronnie leaving her that morning. Gill is at the party and watches her get more and more messed up to the point of playing topless football with some guys and then having sex with one of them on the grass. He picks her up and takes her in his truck. She tries to defend her actions by saying that she begged Ronnie to stay. Gill attempts to have sex with her, but she laughs at him. This infuriates Gill who starts beating her. She isn't moving, so he panics and dumps her out of the truck onto the road.
Lazarus is at a bar that used to be a hot spot because people would come to see him play the blues. Now that bar is pretty empty. His brother comes in and says that he's upset that the meeting Lazarus had with his wife didn't go better and he wanted to try to make sure there was no bad blood between them. Bad blood is an understatement, because Laz smashes a bottle, throws his brother on a pool table and tells him that Cain and Abel would have nothing on them if he ever saw his brother again. A drunken Lazarus goes home and gathers all of his wife's belongings in garbage bags and throws them outside.
The next morning he takes the trash to the end of his driveway and sees Rae laying in the road. He sees she's alive, but realizing a black man would be very suspect if he tried to take a battered white girl to the police or hospital, decides to nurse her back to health himself. She regains consciousness long enough to see he's black and says the name, "Tehronne". Laz goes into town and questions Tehronne about the girl, thinking maybe he beat her. Tehronne tells Lazarus that Rae is the town tramp who has sex with everybody. He says he's not pimping her, so she's free if Lazarus wants a shot at her. Lazarus realizes that Tehronne didn't have anything to do the beating. He goes to the pharmacy and sees Angela the pharmacist. He tells her that he's taking care of his niece because his brother doesn't have any money. She has a cough. Angela gives him some cough medicine and says that it's free.
Over the next two days Laz nurses Rae back to health. She has fever dreams of a man with a zippo coming in to rape her. She also runs out of the house in a daze searching for Ronnie, thinking she can hear the sound of his watch beeping. Lazarus decides he's going to take it on himself to try to make Rae's head right too. To keep her from running off again, he chains her to the radiator. Her fever breaks and she finally comes to. She's obviously upset that she's chained to the radiator and tells Lazarus if he wants sex, fine, she just has to be on her way. He tells her he doesn't want sex, he wants to make her right. She tries a couple times to seduce him, but to no avail.
Lazarus goes into town to get her a dress so she'll for more lady like. He gives Angela a basket of stuff he made from his garden like homemade lotion. They have chemistry. Angela asks how his niece's cough is. Lazarus tells her that she's much better now.
While he's in town, a young delivery boy comes over and Rae jumps his bones. Lazarus comes home and chases him off. The Reverend R.L. also comes over, worried because he's been trying to call Lazarus for days, but he hasn't answered. Lazarus has hidden the phone to keep Rae from calling anyone. R.L. sees that Lazarus has Rae chained up inside and asks if he's crazy. A black man keeping a white woman captive could get himself killed. Lazarus explains the situation to R.L. and asks for help. R.L. goes inside and talks to Rae. Rae tells him that she thinks the idea going to heaven just because you apologize for any wrong you did in the world just before you die is silly. R.L. tells her that he kinda thinks the idea of heaven is a little silly and he feels God is someone you turn to when you need help in doing the right thing in life, not someone you apologize to at the end of life.
R.L., Rae, Lazarus and the delivery boy all share a meal. Rae even helped cook, which is the first agreeable thing she's done the whole movie...unless you count all the sex....but you kinda can't! Anyway....
Ronnie comes home and goes to a bar. Inside he finds Gill. He explains that he had to come home because the army discharged him because of his nerves. He also tells him that he's been unable to get in touch with Rae and asks if Gill knows where she is. Gill tells him that she probably ran off with someone as soon as Ronnie left.
Lazarus and Rae share some post meal moonshine and Laz proposes a toast to freedom. Rae laughs and says that he's funny. Laz unlocks the chain and says it's not his part to try and change her. That's really up to her. She asks if he'll do something for her. He says he'll do anything she wants.
Ronnie and Gill go to Ronnie's house and sees it's exactly the same as when Ronnie left. Gill tells Ronnie that Rae is a slut who sleeps with everyone as soon as Ronnie leaves. He tells him that he even gets with Rae and that's why he knows where everything is in their house. Ronnie flips out, beats up Gill, grabs a gun and leaves.
Lazarus takes Rae into town. He has lunch with Angela while Rae goes to the grocery store to talk to her mom. She tells her mom that all she wants to know is was her mom aware of that fact that she was being molested. Her mom gets defensive and tells her not to put the blame on her because she's a slut. She also tells her that the only regret she has is that she didn't get an abortion. Lazarus sees a commotion at the grocery store, runs in and takes Rae out. Angela follows and asks if Rae is his "niece".
Lazarus and Rae go to Lazarus' old hangout from the beginning of the movie. As they walk in, Rae thinks she hears Ronnie's watch. The bar is packed. Everyone is there to see Lazarus play the blues. Lazarus puts on a great show and everyone dances and has a good time including Rae. Through a window, Ronnie watches Rae dance with all the guys.
Archived footage of Son House tells us that sometime the blues are so bad, they'll make a man kill.
The next morning at Lazarus' home, Rae sings and tries to play a song on the guitar about how much she loves Ronnie. Laz wakes up and tells her he'll play and she can close her eyes and sing. While they play and sing, Ronnie comes in with his gun. Rae opens her eyes and sees Ronnie standing there with the gun to Lazarus' head. Ronnie hits Lazarus. Laz taunts Ronnie telling him if he wants to shoot him for sleeping with his girl, to just shoot him. Ronnie can't shoot him so Lazarus takes the gun away from him. Ronnie starts to have a panic attack so Rae soothes him. Lazarus calls R.L. over to help mediate the situation.
Rae comes clean to Ronnie and tells him that she loves him, but they're both messed up and need each other. She hopes that he'll accept her and help her. They reconcile. Lazarus goes to Angela and asks for one more favor. She's to be the maid of honor at Rae and Ronnie's wedding. Lazarus gives Rae away. As Ronnie and Rae drive off to start their new life together, Angela and Lazarus hold hands. While driving, Ronnie panics when his car is surrounded by semi trucks. He pulls over in a panic and Rae soothes him. It'll be a rough road, but a road they travel together.