Harlee (Jennifer Lopez) visit her ex, Miguel Zepeda, at Rikers Island on his request. He needs a favor: he wants Harlee to find Frank Kovach, a paroled con bragging about committing the murder Zepeda was framed for. Wozniak (Ray Liotta) tells Harlee to leave Zepeda alone - they have bigger problems. He's found the rat, and it's Saperstein (Santino Fontana).
To keep him away from Wozniak, Harlee asks Saperstein for backup on her visit to Kovach - which turns out to be a bust when Kovach pistol-whips her and flees the scene. With Wozniak on the way to meet her and Saperstein, Harlee calls Stahl (Warren Kole) concerned for Saperstein's safety. Stahl and Chen (Annie Chang) arrest Saperstein before Wozniak arrives. But Saperstein manages to give them the slip during a stop to see his mother, so they put out a federal warrant.
On the hunt for Kovach, Harlee and Wozniak find his ex-wife tied up in her home, where she reveals Kovach's plans to abduct their son, Brian. But right as Harlee promises to retrieve the boy, she gets a call from Cristina (Sarah Jeffery), who found Zepeda's letter and is on her way to visit him. Harlee meets Cristina at Rikers and tells her the truth about Zepeda's abusive history, but lies when she says Zepeda is not Cristina's father. Before leaving Rikers, Harlee instructs the prison guard to never let Cristina visit Zepeda.
Pretending to represent Kovach's ex-wife, Tufo (Hampton Fluker) calls Kovach to say he'll help him disappear - Kovach can trade Brian for his girlfriend, a car and some cash. But when Wozniak meets him on the fourth floor of a construction site to make the deal, Kovach pulls a gun and tries to take both his girlfriend and son. Saperstein arrives in the nick of time and tackles Kovach so Brian can run to safety.
After Saperstein fights off Kovach, Wozniak confronts him about talking to the feds. Not knowing Wozniak's intentions, Saperstein admits the FBI picked him up. Wozniak pushes him out of the building, and Saperstein falls four stories to the ground below. Wozniak then shoots Kovach, who also falls. Afterward, Wozniak tells Harlee that Saperstein shot Kovach and they both fell. Everyone is devastated until Tufo examines Saperstein and discovers he's still breathing.
