Detective Daniel "Sal" Salinger is sitting dazed on a curb. In the foreground, the wreck of his Crown Victoria smashed against a light pole. An announcer explains that a recurring nightmare for police officers involves losing their guns. For Salinger, that nightmare has just come true.
Sammy waits in bed as his wife Tami gets ready in the bathroom. Their dog, a retired drug sniffer, starts barking and scratching at the door. Sammy opens the door to discover Tami, his wife, smoking a joint. They argue, but she agrees to flush the pot. "You used to like it," she tells him.
Lydia returns home late to find her mom waiting. They discuss her mom's meeting with a realtor about selling the house; Lydia's mom is excited to be selling her place and moving to Paris. The house will command a handsome price, she tells her daughter. Lydia's concerned that her mom may not like Paris and would have nowhere to come back to. "You need to take a leap of faith too," she explains.
On patrol, Cooper and Ben answer a 911 call at a residence. A woman comes to the door to explain that her partner called 911, but that everything's alright. Her boyfriend comes to the door; his face is scratched. She explains that he cheated on her, so she threw their cat at him. He declines to press charges. Cooper calls it as resolved and they leave.
Sal is wrapping up a quiet dinner date with Mia Sanchez, a local TV reporter. She presses him to come home, but he explains that it's just not right. As he drives home, he's elated, singing loudly to Bob Seger on the stereo; he's had a few drinks. As he's driving, a pair of cars comes racing around a corner toward him, traveling side by side. Sal swerves to avoid them, colliding with a light pole. The crash deploys the airbag and Sal is knocked unconscious. The gangbangers in one of the cars, sensing an opportunity, return to the crash and decide to help themselves to whatever the victim's got. In this case it's Sal's iPod -- and his service handgun.
Nate and Sammy are the first ones on the scene. Sal is their boss and they're unsure how to handle it. Nate wants to call it in, but Sammy knows that Sal's had a DUI before; he wants to keep it under wraps while they get his car fixed and find whoever stole the pistol. They agree to keep it a family matter in the squad for the time being. Sal comes to and provides some preliminary information about the car and the kids who ruined his night.
As Nate and Sammy are talking to Sal to get some leads, Sal hears pistol fire. He recognizes the sound of his own gun. Nate and Sammy race to the scene to find a liquor store with its windows shot out. They quiz the store owner, who explains only that some cars pulled up outside and that she ducked down when the shooting started. The detectives canvass the parking lot and find shell casings -- including a casing that matches Salinger's 9mm.
Sal returns home to find his teenage daughter asleep. He wakes her, concerned that she didn't hear him enter the house. He's scared, because not only have the thugs stolen his gun, they've taken his wallet too -- and therefore know where he and his family live.
Nate and Sammy return to the station to review some surveillance footage from the convenience store. They've also asked for discreet help from their colleagues Kenny and Andy. There's still no official report of the incident; failure to report Sal's crash could land them all in hot water, but they're determined to solve the matter before it turns into trouble for their boss. The video reveals some gang members arguing with each other, culminating in a shooting. They identify one of the gang members as holding a Berreta -- the same model Sal lost.
The next morning, Lydia leaves her house only to be summoned to some bushes nearby by a mysterious voice, asking if she "wants some." She investigates further and discovers a flasher, standing naked from the waist down. She arrests him. On the drive to the station she tries to talk to him about his "problem" and suggests therapy.
Cooper and Ben are back on patrol. They spot a kid standing at the side of a road with a sign reading "Radar Ahead." They question him why he's warning people. He explains it's for the tip money he gets. They explain to the kid that there isn't a radar trap ahead. He says he knows that, but the drivers going by don't. The cops laugh and give him a buck. They answer another 911 call. This time it's a mother teaching her young daughter that if she dials 911, the police will come. Cooper predicts that the day's calls will all be like this -- garbage calls.
The detectives circle the wagons at the station house. They make a plan to put pressure on all the gangbangers they know, call in favors from informants -- whatever it takes to get Sal's gun back. They round up guys on the street, bust parollees, talk to hookers. On Sal's advice they go to visit Big Wayne, a former gang member who's living large now -- the result of a city lawsuit settlement with the police. Told about the missing gun, he laughs, but makes a half-hearted promise to let them know if he hears anything about it.
An angry group of citizens has gathered inside the station, irate at the hassling of young men in the neighborhood. Salinger is equally irate. "There are rules to this game, people. And lines that can't be crossed," he intones. "This is what you get when you enable these guys." Sammy comes to pull him aside; Sal's girlfriend Mia, unaware of what happened to Sal after their date, shows up with a camera crew. Sal comes clean with his Captain, who grants him another 12 hours before requiring him to file a report and instigate an investigation.
The detectives piece together that the ACC gang is involved with the gang shooting and that they're also probably implicated in some big caliber target practice reported inside a local building, Sal instructs them to start tightening the noose. They have Big Wayne's Escalade towed. He shows up at the station to complain. The cops tell him they're serious about scofflaws with parking tickets.
Cooper and Ben Sherman show up to their next "garbage" call, a tough who's upset that a tattoo artist has inked the name "Dennis" on his back, instead of the name Deniece. Cooper makes a snide remark and the thug turns on him, wrestling him to the ground. Ben, noticing that his partner's in trouble, grabs the thug from behind, rolls him over and applies a suffocating "sleeper" hold on him until he goes limp.
Staking out a gangbanger's funeral, Nate and Sammy notice Big Wayne in attendance. They've also searched his impounded car and found some suspicious invoices related to his record business. They're starting to put it together. Still, Nate is uncomfortable with the squad's tactics of hassling the community. "It's a slippery slope, man. This is how it starts," he tells his partner.
Rolling through a gang-troubled neighborhood, Sal notices the house of a long-time resident. She's usually outside in her rocking chair, but is missing today. He stops to check on her, notices gang members inside and forces his way in. With the help of his fellow Detective Kenny, they subdue the gang members and then find the 90-year-old resident of the house locked in a closet.
Back at the station, the detectives compare notes on Big Wayne's record receipts, plus records of former gang members stationed around the country in the Army. Wayne's been using his record business to traffic weapons, including belt-fed automatics, grenade launchers, and high-powered sniper rifles. They get a search warrant and commence to raid Big Wayne's place, discovering a huge cache of weapons.
Stanley, the flasher Lydia busted earlier in the day, shows up at her door to thank her for how she treated him -- and to ask her out for a cup of coffee. She's dumbstruck.
Nate and Sammy stop by Sal's desk with a present -- they've found his gun. "A kid turned it in. The pressure worked," they report. Sal leaves for the day and encounters Mia in the parking lot. He sternly tells her that he can't see her any more. "There's lines, lines that just can't be crossed," he tells her -- and himself.