The BAU are called to investigate the murders of three people: Nate Cochran, 46 who was found in his BMW and a prostitute named Tasha Brooks who was in the car with him. The third victim was Gary Fisher, 42. Ballistics for all three shootings was an exact match.
A man named Danny Lee Stokes arrives back in his apartment after running from the police. There are blood stains on him and he has an extremely bad headache. His roommate Patricia Valdez and her daughter Milena take care of him, telling him that he's doing a good thing, and finding the person who took his mother away from him.
JJ and Morgan interview Lizette Castro, a hooker who works in the same area as the people who were killed. She tells them nothing but JJ and Kate know she's hiding something.
JJ picks up Lizette from a street corner, after offering to drive her home. She convinces Lizette to open up and tell the truth about the night. Lizette tells JJ she was with Fisher before he was killed. She witnessed the murder but got away.
Danny is out on the street when he sees what he thinks is a mugging in progress. He empties his gun at the man, but also think he hits the woman who was being mugged, only she had died of a heart attack.
The BAU profiles Danny as a "moral enforcer" – a type of vigilante.
Garcia examines the background on the latest two victims and finds that the woman wasn't being mugged at all: it was all in Danny's mind. The two victims knew each other as teacher and student.
Danny goes out again, and see what he thinks is a rape in progress in an alley way. He beats the man and then shoots him. The woman runs away.
The BAU later determine the two were boyfriend and girlfriend. They had been making out in the alley before Danny got to them.
JJ and Kate interview the girl, whose name is Lindsay Cooper, who is still high from ecstasy. They learn she had a good look at Danny, enough to work with a composite sketch artist.
Danny arrives home, only to find a policeman coming up from behind him. He turns and shoots him to death, and then realizes that he was just the postman.
Garcia finds out that Danny is the perp, and that his mother had recently been shot and killed in a burglary. Both she and her son suffered from paranoid schizophrenia.
Garcia also discovers that two of the tenants in the same building – Patricia Valdez and her daughter Milena – had disappeared last week, and that Danny had been questioned about it, and cleared.
Garcia tells JJ that Patricia Waldez's ex – a man by the name of David Ruiz – was the prime suspect in the death of Danny's mother. She says he is currently in jail awaiting trial for armed robbery.
She gives the team Danny's address.
Morgan, Reid enter the yard from the front and notice the dead postman.
Morgan knocks on Danny's apartment door and asks to speak to him, but Danny fires his gun through the door, and tells them he has hostages.
Morgan and JJ try to talk him down through the door.
Danny starts to see all of his victims, all covered in blood and talking to him. Danny opens the door, and then drops the gun at Morgan's command. He tells JJ that Patricia and Milena are "outside by the flowers". They go outside and find their bodies buried in the yard.
The BAU arrive back at their office, where Garcia has some pizza waiting for them. She tells them that Cruz has a lot of work waiting for them, in preparation for a Congressional Oversight meeting on Monday.
Kate texts Meg to tell her she'll be working late. She thinks Meg's at home studying. Meg is out with her friend Markayla, to meet "Bobby" on their way to a concert.
"Bobby" sends a text to Markayla, telling her that he's stuck at work. He tells her that his mother is going to pick them up, and that they'll all meet at the concert.
A woman pulls up beside them in a van and tells them that she's "Bobby"'s mother Paige. The girls get in, and the van drives off.