When the police show up at Nolan's home, Sgt. Grey calls Nolan and says Armstrong claims that Nolan shot him and is a dirty cop. They want to search Nolan's home. Nolan tells Grey to get a search warrant, and Nolan calls Wesley to be his lawyer.
At the hospital, Armstrong tells Commander West that Nolan is dirty and that Harper is in on it.
Commander West is furious with Harper for not instructing her trainee to come to Internal Affairs with Armstrong's suspicions. How can IA root out corrupt cops if they are seen as the enemy even by good cops?
Nolan hides the evidence that Armstrong planted in his home in the hot water heater but eventually tells Commander West where to find it. Despite Wesley telling Nolan not to say a word, Nolan tells Commander West everything and then offers to wear a wire to prove that Armstrong is a dirty cop and gets evidence on Reuben Darian.
Harper wants in, but Sgt. Grey won't allow it. She gives Nolan as much advice about this undercover operation as she can.
Angela, Lucy, and Jackson all believe in Nolan's innocence. Bradford has his doubts because he says he's been burned before.
Bradford and Chen go to the prison to find out what Rosalind Dyer spoke to Nolan about. Rosalind reveals that she was watching Lucy's live feed in the barrel and is impressed with her level of defiance and that she refused to show Caleb her fear. She also hints at Armstrong being ready to run.
With further investigation, Angela finds that Armstrong's cell phone shows him at Nolan's house for over an hour yesterday, long enough to plant the evidence. It also show's that Nick was at his wife's gravesite. On a hunch, Angela digs up part of the ground in front of her tombstone and finds Armstrong's go-bag.
Rosalind calls Nick and tells him she's burned him and his go-bag is gone. Armstrong makes a run for it and flees the hospital.
When Nolan meets with the Darians, Armstrong is there, but Reuben turns the tables and plans to kill them both. He shoots Armstrong, but Nolan makes a run for it and manages to double back and arrest Reuben. Armstrong is unconscious and not breathing.
Nolan and Harper receive formal letters of reprimand. Grey tells Nolan that a reprimand, while still a rookie, means he'll likely never move up in the department and always remain a patrol officer.
Later, Rosalind calls Nolan to congratulate him on besting Armstrong and taunts him because Armstrong being a dirty cop means her entire case will need to be reviewed. Nolan hangs up on her.
Wesley finds a pregnancy test in the bathroom, and it's positive. Angela is upset because she wanted to be married first and have the romance before the responsibility. Wesley assures her that they'll look back on this like the gift it is. When Angela is unexpectedly promoted to detective, she decides to keep the pregnancy a secret to make a better first impression at her new job.