Derek Morgan and Jennifer Jareau follow a car in a high speed pursuit. The car crashes and Morgan stops the car. Jareau hears a truck horn and sees a dump truck headed straight for them. She yells to Morgan.
Two days earlier, Corin complains to Mike about the noise in the apartment above them. Upstairs a woman is tied up and banging on the floor. Corin decides to go up and ask them to stop. She knocks on the door but no one answers. A man comes from down the hall and says the noise is his room mate and a girl. He tells Corin that he will ask them to keep it down. Corin leaves and he enters his apartment. He pulls a butcher's knife out of his bag and moves toward the tied up woman.
David Rossi finds Aaron Hotchner still in his office. He is the only one who hasn't gone home. The two go into a meeting room with the rest of the team. Two women have been abducted and later found dead. They were sexually assaulted, shot in the heart, and posed in a praying position, leaning on a cross.
The man from the apartment above Corin's leads the kidnapped women to the woods. She says he won't get away with it and they will find him but he shoots her in the heart.
On a plane the investigating team discuss the victim and the un-sub. They consider that it may be some sort of ritual. The un-sub has no connection with the women but he wants their bodies to be found. Aaron thinks that he may have already found his next victim.
The murderer orders a coffee and the barista says it's free since he works in the mall. She calls hi Wallace and he asks her if she wants to sit by the fountain with him later. She says she has a date though. Wallace finger twitches and hears a woman's voice ask if he wants her too.
A policeman tells the team that another victim has been found in a park. It is only a few mile from the location of the other victims. Rossi and Morgan examine the victim and find that she is different than the others. Her hair is darker and there is a wedding ring nearby. He hasn't touched their jewellery before now and usually targets single women.
Spencer and Jareau speak with the victim's husband. He hadn't seen her for two days because they are separated. Yesterday Emma was supposed to meet him at counselling but she missed the session. He thought that she had changed her mind and wanted to remain with the man she was having an affair with. Spencer and Jareau hypothesize that the killer is either changing his victim criteria or he knew the first two victims were cheaters. They get a list of her best friends from Garcia. They hope that one of her friends know who she was fooling around with.
While a woman showers, the killer enters her apartment. He sneaks towards her while he holds a knife. The woman, the barista from the mall, thinks she hears someone and shuts the bathroom door. The killer hacks into it and she is shocked to see Wallace.
At the morgue, Alex and Aaron question the doctor about what happened to her. There was a tooth found in the victim's stomach but it didn't belong to her.
Wallace talks to a disembodied head in his apartment. He says dinner time and tries to feed the barista a piece of the head.
There has been another victim and she looks nothing like the other three. The previous victims have all been found to have human flesh and bone in their stomachs. Spencer finds something in the newest victim's mouth, a tongue.
Back at headquarters Aaron says that the killer is a white male in his 30's and his victim pool is larger now. Rossi points out that he is trying to convey a message that only he understands. Since the un-sub is forcing cannibalism onto his victims he is most likely delusional. Jareau predicts that he may have been in a mental institute before. The team believes that he is an enforcer and punishes these woman for their sins. They increase police presence in his target area because they fear he may go to more extreme measures to punish his victims. Meanwhile, Wallace is seen buying a snake.
Spencer questions why the killer is forcing the women to only eat from the head. Alex suggests that it may be symbolic, it's the one body part a human can not survive losing. Aaron brings up the fact that he was talked to about the chief job. If he accepts, this will be his last case in the field. He promises to let them know when he decides.
In his apartment, Wallace talks to the head and calls it Heather. He opens the door and his mother is there. She says that Heather has gone missing and asks if he has talked to her. He says no and has a vision of his mother throwing up a tooth. He hears Heather talk to him and he tells his mother to leave.
Spencer asks Jareau what they should do about Aaron's possibility of taking the desk job. Spencer has a realization and thinks he knows why the killer is focused on the human head. All of the victims have been found with flesh in their stomachs and all of this flesh comes from one person. Spencer believes the killer is obsessed with the praying mantis. He explains how the killer walks them through the mating steps of a praying mantis but entirely on his terms. Spencer believes that the head belongs to the woman who is at the core of his rage and now he believes that all women are out to get him.
Wallace has another hallucination of Heather. He yells at her to get away from him. Later in his apartment he feeds the snake he bought to a praying mantis.
Garcia searches missing women in the area and finds Heather Clarke. She went missing two weeks ago and was set to be married soon. There is a DNA sample available and Aaron asks that it be matched against the teeth that have been found.
In Wallace's apartment he puts Heather's head into a duffel bag. He sees a vision of her and chases her around the room. On the floor below, Corin hears all the yelling and noise and goes upstairs to confront her neighbour. She asks what is going on and he tells her that the next time she knocks on his door it will be the last time she comes upstairs.
Garcia searches everything possible and finds that when Heather was 16, she broke up with Wallace and he went crazy. He was hospitalized because of his delusions and Heather had a restraining order against him. The team heads to Wallace's apartment in search of him. They enter his place but he isn't there. They do find a uniform and learn of the restaurant he works at.
Wallace arrives at work late with his duffel bag. He is supposed to work as a chef for a bridal shower. When a waiter brings back a salad and asks for bacon to be put on it, he cuts a few thin strips of skin off Heather's head and uses that as bacon. Patrons begin to notice that the food doesn't taste right. Wallace enters the room holding a gun and the severed head. He says "Good afternoon ladies, time to eat."
The manager at the restaurant asks Wallace to put the gun down and says none of the customers hurt him. Wallace sees some of the women as Heather and threatens them. One hallucination tells him to cut her head off and Wallace holds a knife to her neck. A cop enters and tells him to drop the knife. He does but shoots the cop and runs away.
Aaron and Rossi arrive and chase Wallace into the parking garage but they lose him. They put out an APB for Wallace and an officer responds with his location. Morgan and Jareau are nearby so they give chase. They corner him and Morgan avoids being hit by the dump truck. They arrest Wallace and read him his rights.
As the team flies back to headquarters, Rossi asks Aaron if he has made a decision on the job offer yet. Aaron isn't sure yet though. Alex asks Morgan and Jareau what is bothering them. They explain that Wallace's reaction was bothering them. He was frantic in the restaurant but calm when he was arrested. Aaron receives a phone call and tells the team that they caught the wrong guy. The finger prints from the restaurant don't match the man arrested.
A man that looks like Wallace leaves a gas station when he sees Wallace arrested. Aaron says that there are two things that are never prepared for, twins.