Detective Jarek Wysocki tells police superintendent Teresa Colvin that his niece, officer Vonda Wysocki, radioed for backup on a shots-fired call and got no response because her radio's battery was dead. Colvin explains that the mayor's office is holding up her request for new radios, but she promises to remedy the situation.
Later, Jarek and his partner, Caleb Evans, are pretending to be repo men to lure three crack-dealing brothers out of their house. When one takes off on a motorcycle, Jarek blocks his way with the tow truck, and he too gets arrested.
Meanwhile, the mayor's chief-of-staff, Dennis Mahoney, tells Colvin that the money for her new radios was spent elsewhere. She's not happy to hear this.
Back at the station, drug task force officer Moosekian - unhappy that Jarek and Caleb arrested the brothers - interrupts their interrogation, saying that Colvin wants Jarek and Caleb to meet her at a hospital.
When they arrive, Colvin introduces local philanthropist Amanda Langley, whose son, Teddy, O.D.'d on heroin and wound up in a coma. Amanda says that Teddy was trying to get clean with the help of his girlfriend, Emily, and wants his drug dealer arrested, noting that Teddy's car is missing.
Emily's roommate, Taylor, tells Jarek and Caleb that Teddy met them at a nightclub last night and left angry, but Emily followed him. She hasn't seen them since, but she has Teddy's dealer Mason Goldberg's address.
As Jarek and Caleb arrest Goldberg, they learn Teddy's car was found in a lake - with Emily dead inside. Then Jarek says that he knows Caleb has applied to the FBI, so he wants a new partner. Caleb asks Jarek for another month.
Moosekian cuts a deal with one of the crack-dealing brothers to point out the main stash house, which his task force - including temporary members Vonda and officer Isaac Joiner - will bust later.
Meanwhile, Jarek asks Colvin for assurance that if Teddy killed Emily, there won't be a cover-up. Colvin says that there won't be one.
Jarek and Caleb find Taylor at the nightclub, which is a front for a high-class prostitution ring. When they tell Taylor that Emily's dead, she's shaken, and she shows them files that Emily kept on her computer for "insurance." And one of these files contains messages from Teddy's father!
Jarek confronts Teddy's father, who admits to having had a sexual relationship with Emily, but broke it off before his son, who didn't know this, met her. He also admits to offering Emily money to go away, but she loved Teddy and refused to comply. He says the madam, Julie, was supposed get Teddy involved with another girl. But when Jarek questions Julie, she denies everything. And Taylor tells Jarek and Caleb that, fearing for her life, she's leaving Chicago.
After Moosekian, Vonda, and Isaac raid the stash house, Isaac and Vonda drive away with one of the handcuffed suspects, who pulls a concealed pistol and fires, but misses, and they subdue him.
Meanwhile, mayoral chief-of-staff Mahoney tells Colvin that Jarek is irritating a top political donor, so call him off. Colvin asks whether the donor's money is worth more than her radios.
Taylor suddenly appears at the station, telling Jarek and Caleb that Teddy often threatened to kill Emily, including the night they disappeared. While Jarek receives an envelope from the traffic division, Caleb accuses Taylor of being bought off by either Teddy's father or the madam, Julie.
Meanwhile, the drug task force's leader is furious that the suspect was improperly frisked. But when Vonda claims that she's to blame, he simply tells Moosekian to run a tighter ship. Later, Moosekian tells a concerned Jarek that Vonda just made a rookie mistake.
Colvin calls Jarek and Caleb into her office, where Mahoney demands that the nightclub/whorehouse investigation be dropped. After Colvin tells the detectives to comply, Mahoney says she'll get those new radios.
Jarek finds a politically motivated judge who'll authorize a search warrant. Then Caleb, realizing Jarek illegally accessed his personal file, accuses Jarek of disliking him simply because he's not him.
Once inside the nightclub, they search Julie's office. When Julie objects, Jarek cites various violations in progress, and Caleb seizes Julie's computer as evidence.
After Colvin inspects her new radios, she calls Jarek and Caleb into her office and suspends them. Mahoney wants them fired, but Colvin explains that a fired Jarek will go public, but a suspended Jarek will remain silent to get his job back. OK.
Once Mahoney leaves, Colvin apologizes for the suspension. Jarek explains to the mystified Caleb that this way the nightclub gets shuttered without Colvin's fingerprints on the investigation - and she gets all the information found on Julie's computer files.
Jarek then accuses Goldberg of killing Emily and leaving Teddy to die on the street. A red-light traffic camera captured Goldberg driving Teddy's car - with Emily inside - at the time Teddy was found. Goldberg admits that Emily attacked him for selling Teddy heroin, so he killed her.
When Jarek confronts Vonda about her mistake, she explains that she was covering for Moosekian. She feared he would toss her and Isaac off the task force, but now that she took his bullet, he can't. Jarek smiles.
While Colvin issues the new radios, Caleb confronts Jarek about trying to keep his sleeping with his ex-wife a secret from his partner - a violation of Jarek's own "no secrets between partners" code - and walks away, leaving Jarek staring into space.