Holt gathers Charles, Jake, Terry, and Scully to talk about his and Kevin's upcoming vow renewal ceremony. Then, Holt reveals he plans on retiring from the NYPD. They discuss Holt's retirement plans and agree to keep them from Amy.
The squad arrives early on the day of the vow renewal ceremony to help set up. Jake finds Holt secretly working on the police reform project because of a numbers issue. Jake and Holt realize that O'Sullivan tampered with the numbers.
Jake and Holt gather the squad and catch them up. Jake explains the plan. Kevin approaches the squad, and Holt tells him that Jake was watching porn to cover up their work.
Jake and Holt discuss how they will go undercover at O'Sullivan's house. They end up going as gas workers.
Amy explains to Terry how he will get O'Sullivan's fingerprint. Terry accidentally tells Amy that Holt is retiring, causing her to go into a state of shock.
Kevin asks Charles and Scully where Holt is. Rosa knocks over a vase and blames Cheddar as a distraction.
Jake and Holt discuss how they will get into the basement. They initially go with Holt's plan, but when O'Sullivan's mother refuses to let them in, Holt reverts to Jake's seduction plan.
Terry meets with O'Sullivan. Amy almost foils their plan because she is upset over Holt's retirement. O'Sullivan makes a move that neither of them expects.
Jake gets O'Sullivan's laptop and goes back upstairs. Just as they are about to leave, Holt calls O'Sullivan's mother Mrs. O'Sullivan, making her realize that Jake and Holt are undercover. She threatens them with a gun and locks them in the basement.
Cheddar starts barking, which worries Kevin. Rosa makes up an excuse for the barking. After he walks away, Charles and Rosa argue over using Cheddar as a cover. Then, Rosa and Cheddar stare at each other until Rosa wins.
Terry tries to convince O'Sullivan to give back the lyrics he is holding. Amy goes off on a tangent regarding Holt's retirement, while O'Sullivan starts ranting about Billy Joel. Terry loses it, but he manages to get back the lyric sheet from O'Sullivan.
Jake and Holt figure out a way to contact someone for help.
After O'Sullivan leaves, Terry hands Amy the evidence and reassures her that she will be fine without Holt.
Kevin starts looking for Cheddar. Cheddar starts barking, which leads to Charles, Rosa, Scully, and Kevin finding Cheddar and Jake's case plans.
Jake and Holt have a heart-to-heart. Kevin and Rosa burst downstairs, undercover as cops to get Jake and Holt out of there.
Once everyone is outside, Holt tells Kevin his plans to retire. They talk about the police reform plan and balancing their relationship and their careers.
Holt and Kevin renew their vows in front of the squad.
Two weeks later, Holt tells the squad the commissioner approved the police reform plan and that they promoted him. Holt promotes Amy to Chief. Later that evening, Jake and Amy discuss their parenting schedule with Amy's new job.