NOTE: This spoiler was submitted by Spectre.
We open to the room of Babydoll (Emily Browning). The doctor has just informed her that her mother has died. She and her sister go to the body and cry. Babydoll looks to her stepfather; he just smiles grimly (it is implied he caused her death). Cut to the funeral where the stepfather still has an enigmatic grin and buries his wife. In his study, he studies the will. His wife has left everything to her daughters which enrages him, (implying he killed her for money). Realizing if the girls are dead he will get the money, he gets drunk and decides to do the deed.
He first goes to Babydoll who resists him and scratches his face. He decides against this and locks her in her room while going after her younger sister. Babydoll jumps out the window and get to the front door. Meanwhile. her sister has locked herself in a closet which her stepfather eventually kicks down. He is just about to do something when Babydoll holds a gun to his head. She fires a shot that hits a light bulb missing him, but the ricochet kills her sister by mistake. She raises the gun again but can't kill him. She runs to her mother's grave only to be arrested by the police. Her stepfather is already spinning a tale about killing her sister. They sedate her and her stepfather drives her away.
She comes to as they arrive at an asylum. Her stepfather is having her committed against her will, making her appear deranged. Babydoll notices several things as she walks through, a map, a lighter, a knife etc. They are met by an orderly Blue Jones (Oscar Issac). As they walk, he and the stepfather talk about Babydoll. Blue is being paid so Babydoll can be lobotomized so she will never bother him again (and so he can take power of attorney and steal her inheritance). Blue ups the price from 1400 to 2000 saying he is taking a risk and the Stepfather doesn't want Babydoll lucid when the cops come to find out her side of the story. The other problem Blue has is that they would have to wait five days for a specialist to come in. Blue will forge the papers, he's done it before many times (important later). Dr. Vera is there using music to regress the girls to face their fears.
A montage occurs of what Babydoll considers her time there is going to be like up to the point she is going to be lobotomized by the doctor. Just before the chisel hits we cut away to another reality; this of a 1920's brothel show. Everything we saw is actually girls on stage doing a play performance. Sweet Pea (Abbie Cornish) is in the place of Babydoll who doesn't understand the whole lobotomy thing of the performance. She complains to Vera (now the show's producer) who says they will work it. Babydoll is now an orphan being sold to Blue (the club's owner) by a lecherous priest (in place of her stepfather). Blue is going to sell her virginity to High Roller (Jon Hamm) for a lot of money. Blue tells Sweet Pea to show Babydoll around, but she declines saying she is busy, telling him to tell her sister Rocket (Jena Malone) to do it.
Rocket shows Babydoll around and explains Blue's club is a front for drugs and girls. The girls are dancers who entice customers to want to see more (i.e. prostitution). Babydoll is silent through all this, not able to take it in.
Sweet Pea and the other girls Blondie (Vanessa Hudgens) and Amber (Jamie Chung) speak about Babydoll. They gossip how she's "no virgin" and that she will not last long here. Rocket takes Babydoll's side saying she hasn't done anything wrong.
Vera takes Babydoll and wants her to dance. She will not and Vera tells her that her survival starts here for if she is of no use they will not keep her (meaning she is expendable). Vera starts the music again and Babydoll begins to dance but we don't see it...
We instead see Babydoll outside a large Shaolin temple. She goes inside and is greeted by The Wiseman (Scott Glenn) who asks what she is searching for. Babydoll tells him freedom. He gives her a sword and a pistol and tells her these are the tools she will need. She will then need to retrieve five items; a map, fire, a knife, and a key. The fifth item will be a "tremendous sacrifice" in order to secure true freedom. He ushers Babydoll out and tells her to defend herself.
Outside there are three large samurai warriors. One comes up to her just as she is pulling out her sword. He kicks her through the temple doors throwing her way back. The fight is mainly one sided, as Babydoll is continually thrown around. She is able to pull herself together, and dodges her way to slicing the monster's leg which gives her the chance to decapitate him. The second monster has a chain gun which she dodges the shots to leap up and shoot him several times in the face. For the third and final samurai she lays in wait and lets it come to her. She charges her strike and kills him in one blow...
And we return to the dance studio where everyone is wowed by Babydoll including Blue. The girls all hug her for a great performance. Later that night Babydoll tells Sweet Pea she is escaping before the High Roller comes. Sweet Pea tells her she's nuts about trying to leave.
The next day Rocket is taking some chocolate from the kitchen when the cook catches her. He begins to slap her around and tries to rape her. Babydoll hears it and holds a knife to his neck. Rocket and Babydoll leave.
In the dressing room, the five talk of escape and Sweet Pea is the only hold out, not wanting to endanger their lives. Rocket reveals that Babydoll saved her from the cook which turns all of them to Babydoll's side. Babydoll shows what they need and they realize everyone goes into a trance when Babydoll dances which gives them the chance to steal what they need. Sweet Pea agrees to get the map. But she makes it clear that if the danger gets too much, they will abort the plan.
Sweet Pea goes to Blue and tells him that Babydoll is about to dance so he leaves his office. She sneaks into his office and looks at the map. Babydoll begins her dance...
And we find ourselves in a Steampunk version of WWI. Babydoll, Rocket, Blondie, Amber, and Sweet Pea are briefed by their Military Commander (also Scott Glenn) that they need to go into a German bunker and steal a map before a courier gets away with it. Most of the German army are reanimated corpses powered by steam so they shouldn't feel bad about killing them as they are "already dead." Amber gets into a mechanized walking tank while the other four leave their own bunker and begin slaughtering soldiers. They get to the bunker while Amber takes to the skies and kills opposing planes.
The group gets separated in the bunker. Rocket and Sweet Pea are constantly horded by soldiers and Rocket is surrounded and almost killed by one via bayonet but her sister saves her. Meanwhile, Babydoll and Blondie find the bunker and kill the guards but then Blondie is separated from Babydoll. Babydoll fights the commander but his courier gets away, hitching a ride on a zeppelin. The bunker collapses and buries the commander and Babydoll races out to get the courier. She stops a machine gunner from killer her then uses his gun to bring the zeppelin down, the courier falling back into the bunker. Just as Babydoll gets the map she is cut off by the commander and his soldiers. He is then crushed by Amber's mech and Rocket, Blondie, and Sweet Pea fire on the remaining soldiers. Babydoll hitches a ride and they fly away, mission complete.
Back at the brothel, everyone is star struck again by Babydoll's performance, while Sweet Pea was able to get the map. But not all is well. Blue goes back to his office and feels the warmth on the copy machine. He looks at the map, and notices two pinholes instead of one.
The next day, Blue tells Vera he wants Babydoll to do a headlining dance at the club. Vera says she is not ready and she controls the show. Blue tells her that she may own the show but he OWNS the girls, including her. Blue makes it very clear who is in charge. Vera agrees to his demands.
Babydoll, Rocket, Blondie, Sweet Pea, and Amber talk about stage two of the plan. They need fire. Amber remembers the mayor carries a lighter on him and they devise a move so Amber can pick his pocket. The mayor is showing up that night.
As the mayor shows up, Vera comes out and says Babydoll will be performing tonight though it will be a raw performance due to lack of time to prepare. Babydoll comes out and begins to dance..
We're back in the war zone. The five are told by their commander that they need to infiltrate a castle and kill a baby dragon to retrieve two crystals in its throat that used together will create fire. They are warned not to alert the mother dragon or it could be their doom.
Babydoll, Rocket, and Sweet Pea jump down to the castle where Orcs are battling Knights, while Amber is flying the plane and Blondie is a machine gunner. Babydoll, Rocket, and Sweet Pea find the baby dragon and slit the neck, getting the crystals. The reaction however, wakes the mother dragon and it chases them out of the castle.
Amber gets the dragon to chase them and tries to kill it by tricking it to hit a bridge, breaking it in half. It only makes it madder and it chomps off a bit of the plane, almost killing Blondie. The dragon returns its attention to Babydoll and she jumps through the air and attacks it culminating with her slamming her sword through its head. Mission complete.
Back at the club, everyone applauds including the mayor, who realizes his lighter is missing. The girls celebrate and Babydoll tapes the lighter under her dresser to hide it. Blue comes in and see they are happy. He makes it clear he thinks something is going on and he doesn't like it. He leaves without any direct threats, but it freaks the girls out. Sweet Pea wants to abort the mission, but Rocket wants to see it through. After all they have been through, Sweet Pea is shocked that her sister would choose someone else over her. She leaves in a huff.
Blue's threats are starting to get to Blondie and she begins to cry while getting the music for the third task. She breaks down and Vera asks her what is wrong. Blondie doesn't want to say, but Vera promises not to tell.
In the kitchen (where they have to get the knife from the cook), the four realize Blondie is missing but have to start without her. They barricade the doors and use an old radio for music. They make the cook sit and Babydoll begins to dance. Unknown to them however, the radio has a frayed cable and they accidentally spilled some water which is making its way to the cord...
Back in the war zone, Rocket, Sweet Pea, Babydoll, and Amber are getting on a chopper. Their commander tells them there is a bomb on a train about to hit a major city. They have to disarm and retrieve it before it is too late. They are warned that "time is of the essence."
Amber fires a missile at the train to make an opening while Rocket, Sweet Pea, and Babydoll get on. Their enemies are robots with guns which, they proceeded to cut through in large numbers, the last ones being cut in half by Babydoll and her sword.
They get to the bomb and disarm it and are ready to transport it when disaster strikes. Back in the brothel world, the radio shorts out which brings the cook out of his trance from dancing just as Amber was collecting the knife. Realizing what was going on, he begins to attack the girls and reaches out to stab Sweet Pea. Rocket shields her sister...
Back at the battlefield, a robot they thought they killed attacks Rocket and destroys the jet pack she was going to use to escape. Not only that but it has rearmed the bomb. They cannot stop it now. Rocket shoots Babydoll's rope so she will jettison away from the bomb. Sweet Pea will not leave without her sister, but Rocket doesn't want her to die. She sets off her sister's rocket pack and she is picked up by Babydoll and Amber. The train gets to the city and the bomb explodes killing Rocket. Mission Failed.
Back in the kitchen, the cook has mortally stabbed Rocket. Sweet Pea is inconsolable and Rocket tells her sister to get home and tell their mother she loves her. Rocket dies and everyone freaks. Blue comes in and beats the cook for killing one of his girls. Blue then turns on the girls telling them this is their fault. He orders Sweet Pea to be locked up. He looks to Amber who says nothing. She was able to grab the knife she was stealing before anyone noticed.
Blue confronts Babydoll, Blondie and Amber back in the dressing room. He tells them he knows they are going to betray him and try to escape and he is not happy. He looks to hurt Amber and Blondie cracks, telling him everything. Vera tries to calm Blue down, telling him that his threats of violence aren't necessary as the girls know the jig is up. Blue proceeds to beat Vera and calls her an old whore. He notes that Amber wasn't quick enough to finish the knife task and summarily executes her with a bullet in the head. Saying "nobody likes snitches" he then proceeds to kill Blondie too. Vera and Babydoll break down in tears. Blue tells them they have a show to do and orders everyone out except Babydoll.
Blue tells Babydoll that the High Roller having her "first" is like him being in the sandbox and everyone playing with his toys. He's "taking his toys home." Blue tries to rape Babydoll but she reaches under the dresser to where Amber stashed the knife before she was killed. She grabs it and stabs Blue telling him he will never own her. She steals his master key, the fourth step and races to get Sweet Pea.
Babydoll finds Sweet Pea and tells her they are the only ones left. Babydoll starts a fire and they use the map to get to the main entrance. When someone notices the fire, they pull the alarm, which releases all the locks on the brothel. When they get out however, they realize there are men all around the entrance. Sweet Pea is wondering what they should do when Babydoll has an Epiphany about the fifth step, the "great sacrifice." She has to sacrifice her freedom for Sweet Pea's so by her escaping they all do. Sweet Pea tells her no, but Babydoll says she was the strongest and thus the most likely to survive outside. This wasn't her story it was Sweet Pea's. Babydoll tells her to go, and not let this be in vain. Sweet Pea sneaks around while Babydoll distracts the men, kicking one of the men in the nuts. He raises his fist to strike her and she readies herself...
CRACK. Goes the chisel. We are now back in the real world where the Doctor (also Jon Hamm) is completing the lobotomy of Babydoll. He is freaked out as it looked like in the final seconds she looked at him as if she wanted him to do it. Dr. Vera tells him she is sad patient who in a week, started a fire, stabbed and orderly, and helped a prisoner escape (Rocket, Blondie and Amber are not mentioned but are assumed to have been killed by Blue in the real world). The Doctor asks Dr. Vera why she quickly authorized the procedure when she could have treated her. Vera says she didn't but she is shown her signature on the papers. Blue had forged them like many times before to cover up his crimes. Vera is beyond shocked.
The lobotomized Babydoll is taken to Blue who has her confined to a chair while the other guards watch. He is not happy he was stabbed and says she doesn't get to "leave" until he says so. He is just about to rape her, when the cops bust in. Vera had figured out what he had done. Blue denies doing anything wrong and looks to Vera for support. Dr. Vera finally stands up for herself, shocked that her own negligence had condemned three girls to be abused and murdered and left an innocent girl with a literal death sentence (Babydoll). Vera yells at the police to "GET HIM OUT OF HERE." They drag Blue out of the asylum where he promises to tell him his side. It is heavily implied that Blue in trying to save his own ass, will incriminate Babydoll's stepfather in the lobotomy plot, getting her at least a little justice for everything that happened.
A policeman shines a light on Babydoll's face but it's too late. She's gone. Babydoll is imagining Sweet Pea in the 1920's world escaping to a bus station so she can go home. She is just about to get on when some cops see her and pull her aside to question her (they obviously been sent by Blue to retrieve her back to the brothel). The bus driver (also Scott Glenn) gives her an alibi saying she was on the bus the whole time and cannot be the girl they are looking for. The cops leave and Sweet Pea gets on the bus saying she doesn't have a ticket. The Bus Driver says it is OK. She thanks him and takes a seat, closing her eyes for a well deserved rest.
Dr. Vera narrates the end. She says that in the end, we all have the means to survive anything. That power is inside each of every one of us. She tells us to rise up, find it, and FIGHT.