Harlee Santos (Jennifer Lopez) is a detective at the heart of a tight-knit crew of Brooklyn cops lead by Lieutenant Matt Wozniak (Ray Liotta). The crew often steps outside the law to protect their precinct and their own.
When Detective Harlee Santos (Jennifer Lopez) and rookie Michael Loman (Dayo Okeniyi) hear gunshots at an apartment building, Loman panics and shoots a heroin dealer. However, the dealer was unarmed - a video game was the source of the gunshots. To protect Loman, Harlee concocts a story: the dealer fired first. She uses the perp's gun to shoot through the door and Loman's gut to make the story seem real, explaining, "the truth is in the paperwork." That night, Harlee and her crew, led by Lieutenant Matt Wozniak (Ray Liotta) meet in the walk-in freezer of a tavern, where they pool the cash and goods they've picked up off the street. It's clear their involvement in the community goes way beyond protecting and serving.The next day, Harlee interviews with Internal Affairs Lieutenant Donnie Pomp (Michael Esper) and sells her shooting story successfully, but Wozniak warns her not to take such a risk again - especially for rookie who hasn't yet earned their trust. The detectives ID the dealer's associate, Earl, who fled the scene of the shooting, and find his girlfriend beaten up by rival dealer Raul Torres. That night, Wozniak arrests Earl and hands him over to Raul and his thugs, closing the case and restoring peace to the streets. He asks Pomp, who knew the Loman story was false all along, if he can bring Harlee in on a job, but Pomp says, "Not until we have to."
Meanwhile, Harlee's meeting with a bookie turns out to be an FBI sting, orchestrated by anti-corruption task force Agent Robert Stahl (Warren Kole). Stahl wants her to rat on Wozniak and her corrupt crew in exchange for full immunity. Harlee manages to ditch Stahl to attend her daughter Cristina's (Sarah Jeffery) cello recital, but ultimately, he leverages Cristina to secure Harlee's cooperation - otherwise, it's straight to prison. Since Harlee's familial bond with Wozniak has been securing Cristina's tuition funds, the situation is pretty much ripping her apart. Stahl plants a wire and camera on Harlee's necklace, and the surveillance begins. However, Wozniak tells Harlee he knows there's an FBI informant on the team. She reaches for her gun, preparing for the worst, but he says he wants her help killing the rat, because she's the only one he trusts.
