In Philadelphia, firefighter Cooper is taking his daughter Riley to a concert as a reward for her good grades. Outside the venue, they join a crowd of teenage girls to watch the singer Lady Raven get off her bus. Then they get in line at the entrance and Cooper notices some cops around.
Once inside, he also notices there are officers all over the place. Cooper tries to be a good dad, recording Riley when she joins a dancing group and buying her some snacks. He gets her to talk and learns that at school Riley is always being excluded by the other girls.
As they walk around, Cooper notices more cops and extra security cameras. Eventually they get to their seats and get to hear the opening band while Cooper sees that the cops are in that area too. The concert starts and Cooper has to cover his ears to deal with all the screaming.
After a few songs, he tells Riley he’s going to relieve himself. However once he’s in the bathroom, he actually uses his phone to check on a security camera. It turns out Cooper is a serial killer and he’s checking on his latest victim Spencer, who has been trapped in Cooper’s secret house.
Then Cooper washes his hands and hallucinates his mother is standing there. As more police vehicles surround the venue, Cooper leaves the bathroom and is blocked by Jody’s mom. She explains teenagers are weird sometimes and promises her daughter will start including Riley in activities soon.
Cooper returns to his seat just in time to hear Raven talk about her missing father and how she learned to move on. She asks her fans to use their phones’ flashlights and the place lights up while she plays the piano. At that moment Cooper notices the cops taking a man away from the crowd.
There also are officers in line behind him. During the intermission, Cooper and Riley go to buy a t-shirt but there aren’t any in her size. The seller Jamie promises there are more coming, and Cooper uses the chance to ask about the cops.
Jamie says it’s supposed a secret but shares it anyway: the police has learned that the serial killer known as “the Butcher” would be at the concert, so they came to find him. Every person that leaves is being checked and all the exits except for the backstage are being watched. Cooper laughs awkwardly because he’s the Butcher.
Afterward he drags Riley through the venue while pretending he wants a snack, when actually he’s checking the exits and confirming that they’re all blocked by cops. Cooper notices a drunk woman standing by the stairs and subtly gives her a push to make her fall. The cops at the entrance run to check on her and Cooper tries to leave, only to discover even more officers outside.
With no choice, he goes back to the concert with Riley. Lady Raven announces there’s a special guest and the ground opens for a platform to raise with another singer. Cooper stares at the open hatch and tells Riley it would be fun to get in there to see where it takes them, but Riley calls him out on his weird behavior.
He has to stay not to be suspicious and he stares at the hatch close with frustration. Then Cooper goes back to the t-shirt stand and finds Jamie on his way to the supply room, so he comes along. He notices Jamie using a keycard to access the room so when they’re inside, he pretends to help him move the boxes to steal it.
The topic of The Butcher comes up and Jamie admits he’s been obsessively following the case. He even has some pictures of the victims chopped up in his phone. All the employees got special training for today and even password to identify them, which is “Hamilton”.
After finally getting the t-shirt, Cooper sneaks in the employee’s break room with Jamie’s keycard. The cops are there going over the information they have and they agree that if they find the Butcher, they must take him away from civilians. Cooper hangs Jamie’s card on his jacket to pretend to be an employee and goes through the group to reach the snack table so he can hear them better.
Nearby there’s a picture of his latest crime scene. When a cop asks for sugar, Cooper quickly finds it to look friendly and cooperative. On his way out, Cooper steals a radio from a police bag.
In the corridor, Cooper is blocked by Jody’s mom again and she gets angry when he tries to ignore her. Their argument gets the attention of two cops, but they’re interrupted when they hear a man scream. The two officers rush to the entrance where other cops are arresting the man.
This time Cooper also notices Josephine among them. Back on his seat, Cooper discreetly puts on an earbud and listens to the police radio, learning they’ve already confirmed that the man they arrested was the wrong guy. He was just a thief that panicked because he thought the cops were there for him.
As some officers walk among the seats to arrest another guy, Cooper listens to the descriptions of the men they must look for. One includes a white male in his 30s with an animal tattoo on his right arm, which describes him. Luckily he finds a bracelet on a girl’s bag and puts it on to cover the tattoo.
After checking the venue’s map on the phone, he tells Riley that he forgot his credit card at the t-shirt stand and leaves again. On the radio, he hears that the FBI is setting up tents around the building and barricades on the main streets. Cooper considers pulling the fire alarm, but he notices there’s a security camera watching him.
He also hears Josephine guessing that he would try the alarm trick. Instead he sneaks into the burger stand and messes with the frier. Once he’s gone, a worker checks on the fries and finds two bottles floating in the hot oil.
The bottles suddenly explode and the clients scream in panic, getting the cops’ attention. While everyone is distracted, Cooper steals an apron and puts it on as he goes to the roof. There are cops there too, so Cooper tells them he needed some air after the incident in the kitchen.
The officers confirm his story on the radio but still ask for the code, so Cooper says “Hamilton”. Still unsure, the cops also ask for his card. Luckily Cooper finds a wallet in the apron’s pocket and a venue card that gets them off his back.
Before leaving, he asks about Josephine. The cops explain she’s a profiler who caught many serial murderers in the past. When he returns downstairs, Cooper sees the worker with severe burns and the hallucination of his mother standing next to her.
Afterward Cooper finds Riley, who is worried about his behavior. He tells her that he got cornered by Jody’s mom and Riley asks him not to worry about her classmates anymore because she’s befriended the girls sitting next to her. When they return to their seats, Riley explains this is the part where Raven picks a girl from the audience to go on the stage and even see the backstage.
Seeing that as an opportunity, Cooper approaches one of the crowd handlers and tells him that Riley recently recovered from leukemia thanks to Lady Raven being her inspiration. The cops are getting closer to Cooper’s spot, but luckily his plan works and Riley is chosen to go on stage. They both get backstage passes and the handler talks to a cop to let them pass.
Riley is very nervous but she still goes in when Raven calls for her, and Cooper tries to enjoy his daughter’s happiness while ignoring all the cops near him. In the crowd, Jody and her mom are furious to see Riley on the stage. After the song is over, Cooper notices a girl collapsing and picks her up, asking the workers for a place for her to rest.
He’s taken backstage right before Josephine can see him. Cooper helps the sick girl calm down and even gives her some juice. The manager is really grateful for his help and lets them watch the end of the concert next to the stage.
Cooper asks her if they can leave through the backstage door to avoid the crowd at the end and the manager says yes. Once the concert is over, Cooper hears on the police radio that every male in the venue will be checked on their way out. However when he tries to leave with Riley, he discovers that the backstage door is also blocked by cops.
In a room nearby, Cooper overhears Josephine telling Raven that the cameras will have photos and data of every person that came to the concert. Getting desperate, Cooper approaches Raven and asks her to talk in private about Riley’s condition. They enter her dressing room and Cooper admits he’s the Butcher as he takes out his phone to show her Spencer in the cell.
There’s a button that allows him to release carbon monoxide into the cell, which would kill Spencer before the cops find him. If Raven cooperates, Cooper promises to let him go. Afterward Raven tells the cops that Cooper and Riley are leaving with her in the limousine, so they get to escape without getting checked by the police.
At the main entrance, the crowd is delayed because of the checks and Josephine worries over the lack of results. During the ride, Cooper tells the driver where he left his car so they can be dropped there, however Raven asks Riley if she can visit her home. Riley gets excited and calls her mom for permission, so Cooper can only smile as he gives the driver his home address instead.
Moments later, they’re welcomed by Cooper’s wife Rachel and their other kid. As they go inside the house, Cooper reminds Raven that he’ll kill Spencer if she tries anything. Over coffee and cake, Rachel asks about the concert and Raven tells her about the police operation to catch the Butcher.
The FBI found a receipt for a concert ticket in one of the Butcher’s fake houses so they contacted Raven to make the plan. Josephine has been profiling the Butcher for a while and concluded he’s a white man in his 30s or early 40s, has a position of authority, drives a dark car due to a possible OCD, and had a scarring relationship with his mother. Cooper gets uncomfortable because of how accurate every word is and points out it’s getting late, however Raven offers to play a song on the family piano.
She makes Riley sit next to her and uses the chance to steal her phone. After the song is over Raven says they should take a selfie but Riley can’t find her phone, so Raven tells her to use Cooper’s as she takes it from his hands. After they take the picture, Raven asks for the bathroom and rushes in there with the phone, locking the door behind her.
Cooper starts pounding on the door and his family are weirded out by his behavior. The phone is unlocked and Raven gets to talk to Spencer, asking him for any details he remembers of the area. Spencer mentions things like the door color and a statue nearby, then Raven starts a livestream on her own phone.
She tells her followers all the details Spencer mentioned until one person recognizes the place and sends the police. Raven also texts her driver, who is still outside, asking him to call the cops too. When she checks Cooper’s phone again, the lock screen has gone up.
Next Raven yells that Cooper is the Butcher. She hears weird noises and screaming on the other side of the door, which suddenly opens to show a very nervous Cooper. He takes his phone and checks on Spencer, only to find him gone.
Afterward Cooper takes Raven to the garage, where he grabs his crime bag and pushes Raven into Rachel’s car because Josephine had been right about his vehicle’s color. Raven tries talking to him using a mother’s tone and words, but Cooper doesn’t fall for it. He announces he’ll kill Raven as his last crime and then self-delete to stop the monster.
When Cooper opens the garage, he finds his family blocking the way. He had locked them in Riley’s room but he forgot about the window and the tree next to it. Cooper is in shock because his two lives have finally collided and Raven uses the chance to leave the car.
At that moment the police arrive and take the family to safety while Cooper runs to his closet to move some things. Raven gets in her limo and the usual driver is replaced by a cop so she can be guarded too. The officers burst into the house only to discover a hidden tunnel in the closet that allowed Cooper to escape through the neighbor’s yard.
Moments later, the limo stops and the cop comes to the back seat to handcuff Raven to a metal bar. It turns out the cop is Cooper, who escaped his house while wearing a police uniform. Then he keeps on driving while announcing he’ll take Raven to one of his secret houses to kill her, an urge he’s had since he saw her on the stage.
When the limo stops at a red light, Raven opens the window and tells people to call the police. A crowd gathers around the car and don’t let it advance. While Cooper notices his wife left some clothes in the car, Raven keeps struggling with her handcuffs until the manages to rip the bar off.
She rushes out of the limo as the police arrive, causing the crowd to step back in panic. The officers open fire and destroy the limo, but when they check inside, they find it empty. Cooper has escaped by putting on a hoodie and mingling in the crowd.
Afterward Raven is taken to one of the crime houses, where she thanks her fan for the help and checks on a rescued Spencer. Meanwhile Rachel returns to her house after dropping the kids at her sister’s. Josephine thinks she should be hiding too, but Rachel wants to be here.
After assigning some cops outside, Josephine leaves. Rachel watches the video they’ve found on the security cameras of Spencer’s kidnapping and makes some tea. Suddenly she’s startled by Cooper, who has sneaked in unnoticed.
Cooper thinks his wife set him up, so Rachel has to admit it. Some weeks ago, she started to suspect that Cooper was having an affair, however she realized it was something else because his clothes smelt of hospital cleaning fluid. She also heard him lied to a neighbor in front of her in such a convincing way that it gave her chills.
One day Rachel followed him to one of his other houses and left the ticket receipt before anonymously calling the police, hoping they would prove her wrong. Cooper takes off his shirt because of the smell and grabs a knife, ready to attack. Rachel distracts him by asking him to finish the pie Riley made since today was supposed to be a celebration.
Cooper agrees to eat after seeing Rachel take a bite. He explains how dead victims usually give him a sense of peace, but Rachel has made him angry so he wants to kill her before self-deleting. Suddenly Cooper starts feeling dizzy and realizes Rachel has found the sedatives in his crime bag, which she added to the pie.
As he stands up, he hears his mother and finds her at the door calling him a monster. Cooper cries and tries to approach her, only for the cops to surround him and tase him. A furious Cooper jumps on an officer to knock him out but before he can go for the other one, Josephine joins with another taser and they successfully bring him down.
When a handcuffed Cooper is drag out of the house, he asks for a second to pick up Riley’s fallen bicycle. At that moment the cops bring the kids back and Riley hugs her dad before he’s taken away. In the back of the police truck, Cooper reveals he stole a spoke from the bicycle and now uses it to pick his handcuffs off while laughing.
Later Jamie sees Cooper’s face on the news and freaks out because he helped a criminal.
