The episode begins with Marlo staking out Kevin Ford's house at night, as she's convinced he has a dark secret even though he was cleared of suspicion in Chris's son's kidnapping. When he settles down, she creeps around his house and shines a light in his basement windows. She then peeks through his side door and sees stuffed teddy bears, but he catches her, recognizing her as the cop who'd arrested him before. As a woman walks by with her dog, Marlo calls him a pedophile, and Kevin orders her off his property, threatening to call her supervisor.
Cut to the following morning, with Nick and Andy waking up together, acting cutesy and playful. When Andy asks Nick why he's smiling at her so intensely, he says, "This is a first for me... we were friends and now we're this, not that I'm exactly sure what this is." The two then agree to just stay open and figure things out as they go.
Elsewhere Chris is gracing Dove and Gail, exhausted from an on-going operation, with an optimistic attitude about the changes he's gone through recently. He says, "I've spent the last couple months living for other people, I'm gonna start living for myself again." He asks for a celebration that night, to which a reluctant Dove and Gail agree, for the sake of supporting Chris through his struggle.(Poor Chris, will he ever be whole again?)
In parade that morning, Frank announces it's the last day of Operation Driftnet, the drug bust sting that Dove, Gail, and others have been involved in. The target for the day is a drug deal network being run by Lou Conlin.
Afterwards, Sam notices that Marlo is missing-in-action, and Andy finds her in the station parking lot going through records. In a somewhat manic way, Marlo starts saying that "he"[Kevin Ford] had two mature trees taken down from his yard. After Marlo insists he's not innocent despite Andy pointing out that he was cleared from [Chris] Diaz's case, she continues about the trees, saying that people take down trees for the view and behind Ford's house is an elementary school, which means he can watch children from his house. Marlo then lets it slip that she'd been at Ford's house the night before.
A couple scenes later, while they wait in position for the drug sting, Chloe calls Nick out on shaving, saying that because officers usually don't shave while on a sting, he must be in a new relationship. He repeatedly denies that he's in one and that it's with Andy, but Chloe is convinced he's lying.
Meanwhile, Oliver and Andy (whom Oliver notices is ultra-happy) respond to a call about an assault. Inside the house, they discover signs of a struggle, and that the victim is Kevin Ford, who's alive but unconscious and bleeding. Luke is called in and deduces that because there's no sign of forced entry, it appears Ford knew the attacker.
The woman who'd been walking her dog tells Andy about the fight she saw between Kevin and a woman matching Marlo's description. Without relaying the information to Oliver, Andy takes off claiming she has to take care of something, and calls Sam to tell him to meet her at the station because Marlo might be in trouble. Sam leaves Traci in charge of the sting and heads to the station, where he and Andy find a seemingly off-balance Marlo in the evidence room with papers scattered everywhere. Sam doesn't know what to make of it and Andy tells him about Marlo's bi-polar disorder. Sam calms Marlo down and tells her about the attack on Ford. She swears that she left after their argument and didn't return. Sam asks if the officers are going to find anything that points back to her, and Marlo's uncertain. Sam asks Andy to sign her out and take her home without letting anyone see her, as he heads out to help in another way.
As Andy drives her home, she asks Marlo how she got out of control and Marlo says she fell in love. "I just wanted to feel it like everyone else gets to instead of fearing it... driving it away," says Marlo, who then asks to be taken to her psychiatrist.
Traci spots another customer, but it's a man from the Dowling crew, a rival drug gang, and she's not sure what to make of it. Nick asks what Sam thinks, and Traci tells him that Sam is off dealing with his latest McNally crisis. She tells them to see where the man goes instead of busting him. He gets in to a parked black van. Traci calls Sam, who's arrived at Ford's house, but when he doesn't answer, she makes another call.
Elsewhere, Marlo apologizes for getting Andy involved. She says "I never should have taken photos or gone inside his house..." At this Andy's concern increases. She calls Sam and tells him Marlo went on his computer. To his chagrin, forensics tells him they got a complete print from the device. Sam desperately asks Andy to add an entry to Marlo's memo book to make it look like she was there earlier for the Diaz case. Sam tries to convince a pissed off Andy that it's morally right because if Marlo becomes a suspect, no one will care about Ford and the case will go off the rails. He also insists Marlo didn't attack Ford, and that her involvement could ruin her career, thereby destroying her. He then pleads for her to do it for him, if not Marlo. Andy hangs up, distraught.
Steve arrives to help Traci, and soon Chloe alerts them of a second vehicle approaching. It's Jackson Irving, head of the Dowling crew. He hands a man from the first vehicle a paper bag presumably containing weapons. Traci wants to have the officers move in on the van, but Steve convinces her to wait until the men are in the building, so that the officers can bring Irving and the gunmen down on bigger charges, i.e. conspiracy to commit murder.
At the station Andy adds the entry to Marlo's book just in time, and hurries outside, ignoring Luke calling to her. Frank, suspicious, shows Luke the book 'proving' Marlo was at the house during the Diaz investigation. Luke is suspicious, but doesn't say anything.
While Oliver is on his own canvassing the area, he comes across a young boy whose father has a bandaged hand and bruised face. He's later revealed as Ford's attacker.
At the drug bust, Traci and Steve move in on the building without backup. They tell Lou to stay in his room and then they get in the elevator to meet the gunmen downstairs. Nick, Chloe, Dove and Gail move in with their cars to corner them. The plan works, and the gunmen are arrested.
Later, Luke tells Sam that when his son told him that Kevin Ford tried to lure him into the basement, the man confronted Ford, a fight broke out, and Ford fell and hit his head. Luke says that he's also learned an unknown female officer had gone door to door asking about Ford just a week before. Luke questions Sam but doesn't press him. In the locker room, Nick is distant with Andy, presumably because he's upset she doesn't mention what Traci had said earlier—that Andy called Sam to help her with something.
Gail and Dove arrive home and reluctantly prepare to party with Chris, who's secretly on the phone with Denise trying to help her get Christian to sleep. It's clear he's still struggling with his situation, but when he hangs up, he resumes his cheerful facade and joins his friends.
When Andy encounters Sam on her way home, he tries to reassure her that she did the right thing. Andy asks how it's so easy for Sam to come up with his own set of rules, and says that she wants to follow the normal rules... she wants to be straightforward and hardworking and open. She then tells Sam she didn't do it for him. (Sorry Andy-Sam shippers everywhere, but it looks like this incident has pushed Andy even further away from Sam)
In the closing moments, Traci finally asks Steve out, to celebrate. They banter playfully as they head out together. Elsewhere, Sam arrives at Marlo's. She wakes up from her sleep, apologizes for keeping secrets and asks if he's in trouble. He tells her no one is in trouble. Lastly, Andy finds a downcast Nick at the bar and says she had a terrible day and wants to tell him about it. Forgiving, he welcomes her.