The scene opens with Foster showing a tape to Lightman about a D.C. Police Detective Farr beating up a 9-6 gang member by the name of Prince John. His partner, Detective Wallowsky is in the background only watching. She tells that she got the tape from Internal Affairs and they said that, given Lightman’s relationship with her, that he would help out with this. Foster gets upset that Lightman has a dirty cop working with the Lightman Group. She tells him to stay out of it all. Lightman goes off to visit Farr, who is at the shooting range. He asks if he had any sort of knowledge who Prince John was prior to beating him up. Farr walks away and won’t talk to Lightman, but Lightman pushes on and tells that Detective Wallowsky was seen in the video and that she was only watching. He asks why, but there is no answer. He tells Farr that Wallowsky is also a targe if she knows that is going on.
Lightman and Wallowsky go to the streets and find Prince John. She arrests him and Lightman sees someone watching through a window while doing so. They take him to the interrogation room and Lightman thinks that Farr is dirty and believes that Prince John is going to be killed. However, without any probable cause, he is let go and Wallowsky gives him a ride home. At the Lightman Group, Torres is watching the tape of the incident and sees that Wallowsky has fear on her face. Lightman defends and Foster asks Lightman if he thinks that Wallowsky is clean. Lightman brings up the fact that Foster got the tape to her illegally. Lightman gets a phone call. Prince John has been found dead on the streets. Lightman and Gillian leave with Far and Wallowsky to the scene. Officer Jenkins is also there from Internal Affairs. There is questioning going on when suddenly, Jenkin arrests Wallowsky because an eyewitness tells that Wallowsky was the one who killed Prince John.
Lightman goes to the jail Wallowsky is being held and she tells that she didn’t do it. She tells that Farr is innocent. Farr visits Wallowsky and Lightman leaves. Lightman talks with Jenkins and tells that she will expose her “dirty laundry” off her own and she allows him to talk to Farr. Back at the Lightman Group, Loker listens to the 911 call when Prince John was shock and tells there is something wrong with it. Foster and Lightman go to visit Mr. Phillips, and ask about the phone call. They find out that Luis, her grandson, is a 9/6 member. But, he isn’t there. The head over to where he is headed. They stumble on a crime scene and Farr is already there. Stomper, another gangster, has been found murdered. Lightman tells that same person that killed Prince John, killed two new ones. He tells that he will let Louis punch him if he gives up information. Luis tells that Wallowsky is innocent. However, Lightman’s gaze falls on a gangster on scene that keeps smiling. Jenkins allows Lightman to question him.
They bring the gangster in. His name is Suarez and he is silent and doesn’t give him anything. Lightman asks for all the tapes that involved Farr and Wallowsky’s interrogation of the 9/6 gang members. Lightman, Foster and Jenkins review the tapes and Jenkins says that if Farr is dirty, Wallowsky is also. Lightman meets with Wallowsky and tells that if she doesn’t give up her partner, then she is going to be sent to county jail and she will be killed. Torres and Loker bring in Mrs. Phillips and have her watch a videotape. She tells what happened on the tape. Loker enters and tells that it is “changed blindness” because she saw Wallowsky before and thought it was during. Mrs. Phillips admits that she saw her before the murder and after, but not during. Lightman gets Wallowsky released and she tells that there are two types of the meaning “dirty”. Who you are and what happens to you. Back at the Lightman Group, Foster, Torres and Loker watch the tapes and it is clear that Wallowsky know of the deal that Suarez and Farr had. They start questioning his abilities. Loker tells that Lightman's relationship with Wallowsky has caused "change blindness."
Wallowsky and Lightman are at her place and they are talking about the explanation of why she is who she is. They are interrupted when they hear a car outside. Lightman tells Wallowsky to get the lights and call the police. Wallowsky grabs her gun supply and hides in a closet. Suarez enters the place and shoots the bed with a machine gun. Wallowsky comes out and shoots him and Lightman and her leave. As they are heading back to Jenkins, Lightman tells her that Internal Affairs pressured Foster to pressure him so that he would give Wallowsky up. He tells that he was disloyal to Foster and she is not dirty. Wallowsky comes clean and tells that the reason Farr has been protecting Suarez was because he is Farr’s illegitimate son
Lightman walks up to Farr and tells that Suarez tried to kill Wallowsky and that he has to choose between Wallowsky or Suarez. At the end of his questioning with Jenkins, she tells that Suarez is the one that killed Prince Paul and Stomper for the reason to protect Farr from being blackmailed by them. Wallosky knew all of this and it makes her dirty as well, but Farr refuses to tell that Wallowsky had anything to do with it. Lightman goes up to Foster and tells that Wallowsky is not dirty, but she tells that she doesn’t trust her. She gives Lightman an ultimatium and tells that it is either the Lightman Group or Wallowsky. She asks if she can put Wallowsky in the cube to be interrogated. Lightman agrees. In the cube, Foster tells Jenkins the basics to spot lying. Meanwhile, Lightman teaches Wallowsky how to lie. Torres questions Wallowsky and the machines that Loker has come up with nothing. Foster is not happy with the results and tells that Wallowsky was coached, but when Cal asks her to clear the detective's name, she walks away. Lightman tells that he would have done the same for her if she was in a situation like Wallowsky’s. The episode ends with Farr and Suarez getting carted off to jail. Wallowsky says thank you for lying to Foster and Foster tells that she was staying loyal to Lightman and not her.