When Chris Rios was shot, Reuben Darien called Armstrong to say that Serj had shot a cop and if Serj got caught, so would Armstrong.
Nick knew that Officer Erin Cole was also working for the Darien’s so he had her take the gun out of Nolan’s car. When Erin’s lack of bodycam footage makes her a suspect, Nick tells her that Serj will give her $500K to disappear. Reuben won’t come up with the money. He says Cole will turn on them and he orders Nick to kill her, so he does.
Nick tries to walk away from the Darien’s but Reuben tells him that’s not happening and that killing will be easier the second time.
Nolan shows Harper the bodycam footage but she isn’t convinced that it means Armstrong is guilty so they try to gather more evidence before going to Internal Affairs.
Lopez looks for any type of footage to place Serj behind the wheel of the Maserati. If she can’t find it, he’ll walk. She and Jackson start where the Maserati chase began to look for clues and end up finding photos of Serj in the car.
Cisco Fane is an informant for the LAPD working in the Darien mob. Bradford and Chen track him down and tell him to find Serj.
Nolan remembers what Rosalind said about Armstrong having secrets and goes to see her. Turns out she had broken into Armstrong’s home and found a hidden compartment in the wall with guns, money, and evidence.
Nolan knows he can’t get a warrant so he breaks in on his own but finds the compartment empty. Then Nick comes home, realizes that the compartment has been opened, and sees Nolan’s truck leaving his home.
Grace tells Nolan that although she doesn’t love her husband, she’s going back to him for the good of their son. Nolan tells her he loves her and that he tried to make his marriage work for Henry but it failed. Grace says she’s sorry but she has to try.
Bradford has to miss his last date with Rachel because of a break in the case. He plans to break up with her because long-distance romance doesn’t last but later he pulls her over on the way to the airport and says he wants to give it a try. She happily agrees.
Cisco gives Bradford Serj’s location and SWAT is called in. Nick tries to warn Serj but he's too late and Serj is arrested. Armstrong calls Nolan and tells him he knows it’s over and Nolan can find him at home.
Nolan arrives alone. Nick says he had over $250,000 in debt after his wife died and that’s why he started working for the Armenian mob. Instead of turning himself in, he spins a tale about Nolan being the other dirty cop and how Nick had to kill him when he broke into his house.
Nick and Nolan exchange fire and both are hit but Nolan is wearing his vest. He handcuffs Armstrong who tells Nolan that he planted evidence in Nolan’s home. Nolan rushes to find it, leaving Armstrong handcuffed on his living room floor.
While in custody, Serj tells Sgt. Grey that Nolan is a dirty cop. Just as Nolan finds thousands of dollars in cash and classified evidence hidden in the wall of his bedroom, the police arrive.