We open to the sounds of a woman being assaulted. A naked Everly (Salma Hayek) enters her bathroom, her body shaken from sexual abuse. She flushes the toilet to cover the sound of her taking off the top. Inside, in a plastic bag are a phone and a gun. She calls her police contact, Detective Roberts, frightened. Getting a voicemail, she leaves him a message, telling him, He knows.
Inside the bag is also a locket with a picture of a baby, which makes Everly cry. She then calls another number, getting the voicemail of Edith (Laura Cepada) and Maisey (Aisha Ayamah). Everly hangs up without leaving a message. The men outside her bathroom door are getting more aggressive, telling her to come out now. Everly reaches for the gun, and puts it to her head, intending to commit suicide. However, one of the men breaks through the door and a shot is heard.
It turns out she shot the men that broke through the door. She then goes outside, and shoots the other five men dead, though getting shot in the process. Christmas music plays on the speakers, making it clear the film is taking place during the holidays. Everly's upstairs neighbor, Mrs. Havendash, yells at her to keep it down. Everly can only look up in amazement. She scoffs before collapsing to the ground in shock.
Everly hears a knock on her door. A tenant on her floor, Anna (Gabriella Wright) asks if everything is all right. Everly says 'yes'. Anna comes in and sees all the dead bodies and Everly pointing a gun at her. Anna says she's sorry and quickly leaves.
Everly goes back into the bathroom and calls Detective Roberts again. She screams into the phone for him to call her, and explain what is going on, even if to tell her she is on her own, and he sold out like the rest of the corrupt cops. Everly inspects her wound, and sees the blood pouring out. She hears her phone ring, only to realize it isn't hers. It is the phone of one of the men she killed. Eventually all the men's phones ring and the same man is calling; Taiko (Hiroyuki Watanabe) the crime lord that owns Everly.
Everly takes the phone of the dead man on the sofa and answers it. Taiko realizes immediately that it is Everly and tells her he left her a gift. Everly spots a large red box and opens it. It contains the head of Detective Roberts. Everly is horrified, realizing she is truly on her own. Taiko then reveals that Roberts was only the beginning and then states, the address of Edith and Maisey; Everly's mother and daughter. Taiko says he has his men waiting at their apartment, waiting for his command. Everly looks at the phone in shock and begs Taiko not to hurt them. She tells him that hes right; she should die for her betrayal. Taiko pretends to agree to not harm them, only to turn around and say he will allow Maisey to live long enough to turn her into a child sex slave for his pedophilic clientele. Everly's rage boils over and she screams FUCK YOU! at Taiko and destroys the phone.
Everly grabs her phone and furiously dials her mother, over and over, until she picks up. Everly rips up the floorboards in her kitchen to retrieve a large bag of money she has hidden away for the past couple years. Finally getting Edith on the phone, she warns her mother that men are waiting for them and she needs to take Maisey and run. Edith doesn't understand what she is talking about, but then begins to hear men beating on the door, trying to break in. Over the phone, Everly hears Edith get Maisey and barely escape the apartment into their car. Gunshots ring out and Everly freezes, waiting to hear a response. However, Edith and Maisey escape the apartment. Everly tells her mother to meet her downtown. Edith says she will call the police but Everly tells her he owns the police. Edith wants to know who she is talking about but Everly tells her mother she doesn't have time to explain.
Everly hears the elevator ding and checks the hallway. A man with a shotgun is clearing the hall. Edith is yelling into the phone telling Everly she disappeared for four years and she wants an explanation. Everly crouches to the ground and fires on the man, knocking him back. Everly gets back on the phone, telling her mother that she did not abandon them. Everly tells her that she is going to give them enough money to disappear and if they don't, Edith will be killed and Maisey will be sentenced to a life of misery. Everly tells her mother to call back when she arrives at the meeting place.
Everly hears a cell phone in the next apartment. Looking through bullet holes, she sees her co-worker Zelda (Caroline Chikezie) get a call from Taiko who places a bounty on Everly. Zelda grabs a pair of sais and heads over to Everlys door. Everly waits with one of the dead mens machine guns but she can't control the kick and sprays bullets wildly. Zelda races in and tries to stab Everly with the sais. Everly then forces Zelda to be skewered by one of her own weapons. The shotgun guard comes in and laughs at Zelda so she throws one of the sais at him almost hitting him. Everly goes for the other but gets dragged away by Zelda. As she is being dragged away, Everly is able to grab a gun and fires at Zelda. She misses and Zelda falls down. Everly then rolls over and shoots Zelda in the head.
Everly hides behind her kitchen counter only to be confronted by another hooker who is about to shoot heronly to be killed herself. Everly looks up, only to be shot at by Elyse who mistakenly shot the other woman and is looking to collect the bounty too. Everly sees the phone of the second dead hooker and sees that Taiko put a fifty thousand dollar bounty on her head. Everly tries to reason with Elyse, willing to buy her freedom. Just when Everly is about to convince her, Dena (Jennifer Blanc) comes in, and Dena and Elyse argue over who will kill Everly and wind up shooting each other.
Everly looks out to see Elyse dead, and Dena badly wounded. Despite trying to kill her moments ago, Everlys compassion overrides her survival instincts and she tries to administer first aid. Anna comes back in with a gun. Everly says she knows Anna wants to kill her, but she can help Dena first? Anna and Everly try to help but Dena quickly dies. Anna and Everly point guns at each other. Anna doesnt want to hurt Everly, but if she doesnt, Taiko will kill her. Everly scoffs. "Look around, I can kill you too", she says.
Everly tells Anna that she knows she's going to die tonight, but she has a mother and a daughter to keep safe and needs the time to make that happen. Everly speaks to Anna, noting she was a mother once too which only makes Anna more unstable. Everly tells Anna she rather not give Taiko or one his men the satisfaction of killing her and would rather let Anna do it. Anna questions why she wouldn't just run, but Everly says that Taiko will never stop hunting them until Everly is dead. If she dies, he wont care anymore. Anna nods and tells Everly she will give her two hours to make her final arrangements before delivering herself to Anna to die.
Everly sees the shotgun the guard left behind and picks it up. As she walks back, her next door neighbor charges out of the room. Everly quickly shoots her dead and shuts the door.
"That's a lot of dead whores", the man on the couch, only known as Dead Man (Akie Kotabe) says. Everly is shocked that he is still alive, seethes in rage at his comment. "You don't get to call them that. Get up", she says but he wont. It turns out the bullet that hit him has severed his spine, making it impossible for him to move or feel pain. Dead Man inspects Everly and tells her that her wound is rather minor compared to his. Dead Man asks for a glass of water and Everly begrudgingly gives him one. She uses some liquor to sanitize a wound on her hand and winces in pain. Everly sees Dead Man apparently smiling at her pain and takes away his water.
Everly looks outside and sees four of Taiko's men and an attack dog outside waiting for her. Nevertheless, she grabs a pistol, the shotgun, and her bag of money and goes to the door. Tell Taiko to lick my balls, Everly says as she opens the door. A shotgun blast nearly hits her and she closes the door. One of Taiko's men calls her a bitch. Everly opens the door and fires off a shotgun round. "I'M NOBODYS BITCH!" she screams, heading into the next door apartment. We see it is the shotgun guard with a new weapon. He then pulls out a grenade and throws it into the room Everly went into. The explosion throws her back in her apartment. The shotgun guard has the drop on her but the Dead Man distracts him so Everly can pull out her pistol. She then shoots him in the genitals and the chest, killing him.
Everly gets a call from her mother saying she is at the meeting spot. Everly says she is on her way.
Everly hears sirens and curses. She looks outside to see police on their way. She locks her door and turns on her television which is hooked up to security cameras for the whole building. Dead Man cannot believe she has a system like that. Everly shrugs. You know how much he likes to watch, Everly deadpans. Everly watches as the police evacuate the building with the rest of tenants save for the delusional Mrs. Havendash. Everly, seeing the coast is clear plans to run. Dead Man requests that Everly kill him so he doesn't have to face Taiko, and comments he didnt participate in her gang rape. Dead Man says he was only following orders which Everly says that of course absolves him of responsibility. Dead Man says no, but Taiko has made him do horrible things including human trafficking and sexual slavery, by putting the fear of being killed into him. That is Taiko's main weapon; the fear of death and having the ruthless nature to always carry it out at his leisure.
Everly goes to leave, but Dead Man begs her to destroy the tape before Taiko sees it. Everly looks back and realizes that there was even a camera. Dead Man warns her not to watch it but Everly does. We don't see anything but we hear the audio of her screaming and Everly's pained horrified reaction. Dead Man looks on in stoic remorse. She puts the tape in an alcohol drink and lights a match, destroying it. Everly points a gun at Dead Man. Our worst day could be a blessing in disguise, he says. Everly leaves him without killing him and makes her escape. Dead Man watches on the camera feed and actually cheers her on, hoping she will be able to make it out. However, at the last moment she is caught by the police officers still in the building. They work for Taiko too. They throw her back into the apartment, telling her Taiko will deal with her soon enough.
Dead Man asks her what she will do now, and Everly tells him to shut up. Dead Man tells her a proverb his grandfather used to say, which gives Everly the idea to make Edith and Maisey covertly come to her apartment, get the money and disappear. Realizing the place is filled with corpses, Everly hides the bodies the best she can and cleans up the blood. In addition, she gathers up all the weapons; the pistols, the shotgun, the grenades, and a heavy machine gun and hides them throughout the apartment. She then takes a shower and squirts soap into her wound, making her cry out in pain. She then tends to it with a bandage kept in place with duct tape. Putting on a sun dress, Everly asks Dead Man if he thinks Maisey will like it. Dead Man replies that she perhaps should wear something a bit more practical given that her fight is not over. Everly agrees and changes.
Dead Man asks for a final request; a cigarette. Dead Man says he doesn't understand how she got to the police. Everly explains that they came to her; a cop arrived undercover as a plumber and convinced her to turn on Taiko. She was frightened every minute thinking Taiko would find out but went along with the idea that if he was out of the way, she could finally be free and rejoin her family.
Everly gets a call from Edith, who is walking into the building. Everly coaches Edith on how to fool the Yakuza men into going up to the seventh floor. However, Edith slips at one point, giving the man in the elevator suspicion. Everly races to the elevator, grabbing one of the sais still embedded in the hallway and hides as the door opens. She then stabs the man, getting into a hand to hand brawl. Everly eventually gets the upper hand and stabs the men dead in the throat and gets another gun in the process. Edith and Maisey come down via the staircase and go to Everly's door.
Everly opens the door and says hi to her mother and Maisey, overcome with emotion. Edith asks if they can talk inside, but Everly firmly tells her that she has to take the money and go. However, Edith forces her way inside, and will not take no for an answer. Everly gives Maisey a long overdue Christmas gift; a large Pink bear which Maisey loves. Maisey shows Dead Man the bear and he says it is very beautiful, like you (obviously feeling deep remorse and shame for what he put Everly and her family through). Everly once again tries to make her mother leave, but Edith will not leave without answers and pulls Everly into the bathroom to get them.
In the bathroom, Edith screams at her for abandoning both her and Maisey, for not contacting them, and putting her through unbelievable stress and heartache. However, Edith is just glad that Everly is alive. Still, Edith wants to know what happened. Everly tells her mother that there are so many things she wants to tell her, but there is literally no time. Everly does tell her that she was taken against her will to be someones slave and she has been locked up in the apartment for four years. Edith, even without the full picture, realizes the scope of her daughters torture and tells her she is so sorry.
Maisey is with Dead Man and begins to look around. Not wanting her to see anything horrible, Dead Man distracts her with the Itsy Bitsy Spider song.
Edith asks who Taiko is. Hes the Devil, Everly replies. Edith asks what he did to her. Did he torture you? Edith asks. Everly says she was one of the lucky ones; she wasnt trafficked overseas or sent to a dungeon to be raped constantly which makes Edith recoil with horror. Everly says that her punishment was losing her child, her family. Edith tells Everly they are leaving together, but Everly says she needs to leave without her. Edith hears a phone ring and discovers three of the dead Yakuza men, the very men that raped and planned to murder her daughter. Everly tells her that is what Taiko is; he is a bringer of death and asks if Edith finally understands why she needs to leave. Edith nods yes.
Dead Man, quite near death, wakes up to see Maisey is gone. He calls out to her, only to find she has found the box with Detective Roberts head. She wants to open it but Dead Man says that will not be wise, and yells out to Everly.
Back in the bathroom Edith realizes that Everly will not be leaving alive. "Sorry Mama", Everly says.
Everly finally hears Dead Man and rushes out, and stops Maisey moments before she opens the box. As they tend to Maisey, Edith gasps and Everly looks to see that Dead Man finally succumbed to his wounds. Everly closes his eyes and appears to have a moment of sadness for him, given he spent his last hours apologizing for his role in Everly's plight and in his last breath, shielded a child from the horror he took part in. They cover his body with a sheet.
Everly hears a dog bark and realizes Maisey went into the hallway, where a guard and attack dog wait. Everly carefully grabs Maisey and runs into the apartment, handing her to Edith. The dog attacks Everly but gets confused, biting Dead Mans leg instead. The guard tries to tell the dog to kill Everly but he doesn't understand. Everly grabs a grenade and throws it into the hall, and the dog mistakes it for a ball and runs after it. The guard tries to stop the dog, but the grenade explodes, killing them both.
Everly checks the security feed to see an elevator of Yakuza men, plus one in the staircase are coming up to kill them. Everly grabs a grenade and the shotgun, surprising her mother. Everly goes to Anna's door and begs her to open up and shield her family. Anna finally opens the door and says she is doing it for Maisey and that their agreement still stands. Everly says she understands and shuts the door. The Elevator opens and the men stare at her. The one in the staircase rushes out, so Everly shoots him, knocking him into the elevator. Using their disorientation to her advantage, Everly throws a grenade inside, and as the door shuts, it explodes, killing all inside and causing the elevator to fall to the ground floor. Everly looks to the cameras, to now see there are now a team of heavily armored killers waiting for her. As she goes for a gun, she doesn't notice a man in a white suit enter the building. Then the power goes out.
A man in a steel cage is wheeled in along with the man in the white suit, who calls himself The Sadist (Togo Igawa). The Sadist lets the caged man, The Masochist free, who charges Everly. Everly shoots him several times, only for The Masochist to fall on top of her. Unable to move, The Sadist disarms Everly and puts her in the cage, binding her arms with rope with the help of his four feudal costumed helpers.
The Sadist describes himself as a makeup artist and outlines his specialties; sulfuric acid, battery acid, gasoline, and sodium hydroxide, all of which will be used to disfigure and torture Everly. To further toy with her, he pretends to pour acid in her eyes when it is only water. Meanwhile, Mrs. Havendash makes noise upstairs so The Sadist orders one of his men to shoot her. The man fires into the roof, killing her.
The Sadist begins his work, making his men use a stun gun on the cage to disorient Everly. He then pours acid on her hand, near the rope which begins to fray it. Then he pours some on her leg, burning skin and making her cry out. Before he can pour it in her eyes, Edith shows up and kills two of The Sadists helpers before being knocked out. The Sadist orders Edith to be brought to a nearby chair, in order to torture her in front of Everly. The Sadist pours gasoline down Ediths throat while Everly struggles with the frayed rope. She finally breaks free, and grabs a gun from one of the helpers, killing him, wounding The Sadist, and killing the other helper. Everly makes her mother induce vomiting to throw up the gasoline when The Sadist attacks again. When he tries to kill Edith with a sword hidden in his cane, Everly disarms him and pours acid down his throat. It liquefies his body from the inside out. The Sadist calls it a fitting end as his guts drip out of him and he hits the floor, dead.
Everly gets a call from Taiko. Everly asks if he has had enough. Taiko says no, he has been enjoying himself for the past few hours. Everly looks across the street at the building and sees Taiko sitting with one of his men in a sniper position. He had been watching the entire time, and could have killed her at any point but chose to let her fight continue. Taiko then says it is now time to let her truly suffer and has his sniper shoot Edith. Everly holds her mother as she dies in her arms. Taiko laughs maniacally telling hes not doing with her yet.
Everly, having enough, pulls the large machine gun out of the oven and walks over to the window. Taiko sees this and tells her that is not a good idea. "Fuck You", Everly says, and sprays the building with machine gun fire. In response, Taiko's man shoots a LAW Rocket into the apartment, engulfing it in flames. Everly is only able to find a safe spot with seconds to spare. Taiko calls out to Everly and when she doesn't immediately respond, he beheads his sniper for denying him Everlys death. Everly then walks out to the window and glares at Taiko. Taiko then leaves the building he is in.
Suddenly, smoke grenades fill the apartment and Everly runs to take cover. A four man squad enters her apartment. Hiding under the floorboards, Everly covertly kills three of the men. As the second squad enters via the windows, Everly shoots one out of the apartment window before being shot and subdued by the remaining men. Taiko enters, and orders Everly to be put on the bed with a noose around her neck, and then tells his men to leave.
Taiko then takes the sword and slides it around Everly's body, taunting her. Everly says if he is going to kill her, just do it already. Taiko says it wasnt going to be that easy. Everly asks him "why though?" He was there the entire time, and could've ended it hours ago. Perhaps he cannot bear the thought of her dead after all. Taiko then cuts her cheek and says perhaps he will get Maisey to watch Everly die. Taiko asks Everly if her daughter knows she is nothing more than a used up whore. "Keep my daughter's name out of your mouth!" Everly screams, kicking him in the face.
Taiko swings his sword but only winds up cutting the rope, freeing Everly. He then digs his finger into her new bullet wounds, wanting to continue his punishment. He throws her over the bed, and slings his blade into the floor making it stick. He tells Everly dying by his blade is not an honor worthy of her and pulls out a small knife. Taiko tells her he intends to take her back tattoo as a souvenir. Everly sees a shard of glass and reaches for it. She gets it and breaks it off in his leg. As he pulls out a gun, Everly grabs a taser from one of The Sadists helpers and shocks Taiko several times. As she holds a gun on him, Taiko says if she kills him, Maisey and her will never be safe. Everly hands him the small blade and tells him to "Die with honor. Do it yourself". Taiko pretends to comply, then throws the blade into her shoulder, wounding her. But Everly got off a shot in return, grazing his head. As she pulls the blade out, Taiko gets ready to charge her. Taiko runs towards her, but Everly grabs his sword and stabs him completely through his body. She then proceeds to twist the blade, then pull it out vertically, cutting him haphazardly in half.
Back in Anna's apartment, Anna has put Maisey in the closet with her bear, and tells her to be quiet and don't move. Anna, though unwilling to harm a little girl, isn't above stealing Everly's money and running. First though, she calls 911 to report Maisey's location. However, someone breaks into her apartment and kills her. The 911 responder hears it all and sends units to the apartment.
Maisey leaves the closest, oblivious to Anna, dead, right behind her. She goes outside in the hallway, calling for her grandmother. Behind her, is The Masochist, still alive (he is the one who killed Anna). Maisey closes her eyes and tries to calm herself while The Masochist is standing behind her with a meat cleaver telling her to turn around. A gun shot is heard, and The Masochist drops dead.
Everly is in the hallway, with a gun. She calls over to Maisey, telling everything is okay. Maisey tells Everly that she knows she is her mother, that she has her picture in her room. Everly gives her daughter her locket and tells her to think of her. Maisey asks why Everly was gone so long. Everly tells her she missed every moment and never stopped thinking about her. Everly tells Maisey that she loves her, always. "I love you Mommy", Maisey replies.
Maisey looks at Everly. It appears she has died from her wounds. In that moment, the real police show up (i.e. ones Taiko hadn't corrupted) with EMTs. A SWAT officer pulls Maisey out of the building as the EMTs work on reviving Everly. A slow pan of the building shows the destruction of the past few hours. As the camera pans up to the sky, an EKG flat line is heard. That flat line turns into a heartbeat rhythm. A loud gasp is heard. It appears that Everly will survive after all and will be able to build a new life with her daughter.