Memorial Day morning, Ben promises Daisy he'll attend her concert tonight. Dewey stumbles from a bar after an all-night bender. Though he's in no condition for duty, he dresses for work inside his car. John greets Cesar, his friend who's building a retaining wall for his garden. Sal, who lives across from Russell's house, invites Russell to his annual neighborhood barbecue. He tells Russell, who's living in a guest house after a fight with Dina, that she misses him. A married couple across the street argue loudly. Sal bickers with his 15-year-old daughter Kimmy, who's made other plans, about attending the barbecue. Tired of the shouting neighbors, he goes to break it up.
A pedestrian with car trouble flags down Ben and John. He wants LA's finest to take him to his appointment, but John says they aren't a taxi service. The man demands they call him a cab. "You're a cab," John says, earning a hurl of petulant insults from the self-important man.
Detectives Nate and Sammy learn that Marta Ruiz, matriarch of the Avenue drug family, was released after posting her million-dollar bail, even though she's facing ten different felony charges. A Mexican national, ICE won't deport her due to her political asylum status -- the drug cartels will kill her if she returns to Mexico. Sammy worries they'll make another attempt to kill Janila, who is testifying against Marta's sons in a drive-by shooting. At the station under Sammy's watch, Janila says she's going to work out with the Explorers. Sammy tells her to stay close.
Marta interrogates a gang soldier, who failed to kill Janila outside the courthouse, on why he hasn't succeeded in killing a chubby little girl. He says she moved, and it was near impossible to kill someone downtown in broad daylight. While he's distracted, another gang member shoots him in the back of the head. In the judge's chambers, Marta's son's lawyer asks for a continuance, even though he'd previously said they were ready to go to trial. Sammy goes ballistic, accusing him of stalling so the Avenue gang can get another chance to kill Janila. He even asks the lawyer if Marta's threatening him, too.
On patrol, Chickie confronts Dewey about smelling like booze, saying he should go home sick. Dewey insists he's fine; besides, he's out of sick days. When Chickie presses the issue, he angrily denies having a drink in the last two days, then immediately contradicts himself when he says he hasn't drank since yesterday. She calls him on that, which takes the wind out of his sails. He says he has a couple of days off soon and promises to handle it then.
Sammy leaves a message for Tammi, who hasn't answered her phone all day. He asks Nate if Tammi could be having an affair. Nate asks how their sex life is, which Sammy says is great. At that, Nate assures his partner that Tammi isn't screwing around. Later, Rico, an FBI agent working on the federal aspect of Marta's case, offers help to get a new charge on her so they can arrest her again. However, Marta's managed to skate on her federal charges so far. Sammy notices Janila's been gone a while and tells everyone to look for her.
John and Ben respond to a homicide call. Chickie and Dewey are already on scene, standing on a hillside near Dodger stadium. In front of them, the handcuffed, executed Avenue gangbanger lies cramped inside a wardrobe case. After the detectives arrive, Ben gets a call from Daisy and assures her he'll be at her concert. Dewey leaves the scene to "take a leak" and Chickie tells John and Ben about him smelling of alcohol. She says she's going to turn him in, and John encourages her to do it, even going so far as to say he'll do it if she doesn't.
Sammy and Nate realize Janila has given them the slip, not having been to Explorers since yesterday. They track down the address of Marquis, her ex-boyfriend who's a Grape Street gang member. They race to get there and find Janila, who's not happy to see them but goes with them. After they leave, Marquis makes a phone call. At a burger stand, Nate assures Janila she's doing the right thing and says he understands that she misses her friends. Sammy calls Lydia to take her up on her offer to let Janila stay with her.
Sal obsesses over Kimmy's Facebook page as he talks to his wife, who says Kimmy is staying with a friend tonight. She encourages him to trust their daughter, but he's not about to. Marquis is escorted to the Avenue gang hangout by a few members. Inside the house, he tells Marta that the police got Janila and that he doesn't know where she is. Marta reminds him that Grape Street owes them money. He promises to find Janila's new location with a little more time. Marta warns him that if he screws up again, she'll have his whole family killed.
Detectives Kenny No-Gun and Andy Williams ID the dead gangbanger as Camilo "Chuco" Salazar. Sal, still on Kimmy's Facebook page, interrupts them to ask what "sexting" is. They confirm that it is what he thinks it is. He glares at the page, where Kimmy is being willfully encouraged by one of her friends to try it. Sal says he's going to kill her.
John and Ben respond to a call of a screaming woman. Upon arrival, they find the woman called 911 because she was irate that the fast food restaurant she's been going to every day for fifteen years is out of Chicken Nuggets. Ben suggests she tries the fish sandwich. Nate and Sammy drop Janila off at Lydia's, and John and Ben are assigned to work security detail outside her house. John tells Ben he'll try to get him covered so he can go to Daisy's concert. Meanwhile, Lydia tries to make inroads with Janila, finally succeeding with the offer of a barbecue and movies.
Dewey pulls over to relieve himself once again, and Chickie takes the opportunity to call the sergeant to report him. Sammy finally gets ahold of Tammi and chews her out for ditching Janila. She yells back at him, and he apologizes, realizing he overstepped his bounds. When Sal finds out through Kimmy's page that she's going to a rave, he leaves to stop her. Kenny and Andy offer to go with him. Meanwhile, outside Lydia's house, John and Ben stop Marquis when he approaches the door. Even though Janila vouches for him, Lydia and the cops say he has to leave.
Under a bridge, Chickie waits in the backseat of their patrol car as Dewey sleeps behind the wheel. When he wakes, she tells him she turned him in and that the sergeant is on his way. Enraged, Dewey speeds off with Chickie trapped in the back. Ranting that she's not going to turn him in, he drives recklessly through the LA river as Chickie screams at him to stop. He drives up the embankment and flips the car, sending them sliding upside down until they scrape to a stop. Injured, Chickie manages to radio for help as Dewey lies bloodied and unconscious. Ben and John leave their post to respond.
At the accident scene, Dewey is wheeled off in a gurney while paramedics tend to Chickie's superficial wounds. Russell takes Sal's advice and comes home to Dina, who's glad to see him. They apologize to each other and make up.
Later that night, Sal, Kenny and Andy search the rave for Kimmy. During their search, Kimmy calls her dad, high on ecstasy, to say she loves him. She's left the rave, and hangs up before he can get out of her where she went. To get rid of the security detail, an Avenue gang member makes a bogus call to 911 and reports an officer shot at a location near Lydia's house. The security detail speeds off, leaving the house unguarded. At the station, Sammy sees a report of the call and becomes suspicious, but Nate thinks he's being paranoid.
At home, Lydia's motion sensor light illuminates outside a window. Trying not to alarm Janila, she gets her gun. Another light triggers and a dog barks, prompting her to run upstairs for her shotgun. Janila follows, frightened. Lydia calls for backup just as glass shatters downstairs, then gives Janila her handgun and shuts her in the bathroom. She sees a man downstairs and blasts him dead, then checks for more intruders. She hears someone upstairs and sneaks up on him, killing him just as he's about to shoot a terrified Janila. The other gangsters flee with Lydia firing behind them as they blindly fire back with AK-47s.
D.A. Deborah Janowitz arrives at Lydia's house among the throngs of detectives and police. She tells Sammy that she's secured witness protection status for Janila and that the U.S. Marshals are on their way to pick her up. Sammy sarcastically says, "Now you have the money." The prosecutor doesn't make excuses, just says that's the way it is. Sammy goes back to comfort Janila.
After work, Ben goes to Daisy's concert, only to have her tell him that she's going back to New York tomorrow to reunite with a past flame. She explains that she thought she was done, but they've been talking and are going to try again. She's very sorry, and Ben is disappointed but understanding.
At Sal's barbeque, Kimmy returns home, crying and contrite for her behavior, if not a little scared. She falls into Sal's arms. Russell walks with Dina to Sal's and they pass the fighting couple. Dina says the wife said her husband lost his job, so Russell decides to invite them over. At home, John admires his retaining wall and garden with Cesar. They admire each other as well as the Memorial Day fireworks light up the sky. Sammy makes peace with Tammi and they cuddle on the couch. In Sal's backyard, they watch the fireworks. Dina sits among them.
Russell knocks on the neighbor's door. Larry opens the door and points a gun at him. All cop instincts gone at the shock of his neighbor turned psychopath, Russell holds his hand up and says "Don't," but Larry fires, hitting him in the chest. At the barbecue, Sal turns at the sound of the gunshot, but it's cloaked by the fireworks. Larry goes inside, shoots his wife. This time, Dina thinks she hears something. As Russell lies helpless, fireworks erupting in the sky, Larry shoots himself.