Peralta and Santiago are sent undercover to catch Brooklyn's most notorious identity thief. As the case progresses, they discover that working together has brought them closer than they used to be.
When Chief Madeline Wuntch allows Peralta to work on his dream case, Captain Holt worries she's setting him up to fail. Jeffords organises a field trip hoping to get his daughters into a top school.
Peralta is excited to work on a case with Dave Majors, the best detective in the NYPD, until Majors reveals he intends to ask Santiago out. Gina and Boyle try to stop Jeffords taking a new job.
Peralta injures himself chasing a suspect but refuses to take time off work to recover. Holt and Diaz have an awkward dinner date with their significant others, so they invite Santiago and Gina along.
Santiago and Diaz investigate Peralta's claim that somebody is trying to sabotage his professional life and get him fired. Boyle partners up with Hitchcock and Scully in order to solve a tricky case.
Peralta's father Roger, an airline pilot who hasn't played a big part in his life, comes to town to spend time with him. Holt sets an impossible brain-teaser for Santiago, Jeffords, Gina and Diaz.
Each member of the squad is given a task to complete for the wedding of Gina's mother and Boyle's father. But Peralta and Santiago get side-tracked and Jeffords struggles to officiate at the ceremony.
When Peralta notices that Captain Holt is in a bad mood, he teams up with Holt's husband Kevin to find out what has gone wrong. Boyle tries to get a confession out of an elderly bank robbery suspect.
The squad is invited to a Homeland Security counter-terrorism training exercise, where the agent in charge assigns them the role of hostages. Gina administers a psychological test to Captain Holt.
When Sophia's job gets in the way of her relationship with Peralta, he tries to win the favour of her boss Geoffrey. Deputy Chief Madeline Wuntch needs Captain Holt's help with a job recommendation.
The squad decides that it's high time Peralta paid them back all the money they have lent him over the years, while Santiago and Captain Holt team up to re-open the Brooklyn Broiler arson case
The team is excited to visit Boyle's beach house for a detectives-only weekend getaway until Peralta ruins the fun by inviting Captain Holt. Boyle helps Diaz send romantic texts to her new boyfriend.
Peralta and Boyle go on an eight-day stakeout, putting a strain on their friendship. Jeffords writes a book for his daughters. Holt's nephew visits Brooklyn and makes an instant impression on Diaz.
Doug Judy is back in custody after scamming Peralta and Diaz when they last met, but Captain Holt offers him a plea deal
In an attempt to add a touch of romance to their work trip, Peralta invites his girlfriend Sophia, as well as Santiago's boyfriend Teddy, to join them at a B&B. Diaz refuses to admit that she is sick.
Peralta and Boyle reluctantly join forces with Agent Jack Danger, a pompous investigator at the US Postal Inspection Service, to catch a drug dealer. The team try to help Santiago give up smoking.
Peralta is left in charge of the precinct at Thanksgiving because Holt and Jeffords are out of the office, but chaos ensues when a mysterious powder-filled package is delivered to the building
Peralta hits it off with a woman he meets in a bar, only to find she is the defence attorney representing a perpetrator he is trying to put in jail. Diaz pressures Santiago to stand as a union rep.
When an Internal Affairs investigator reveals that there may be a mole in the precinct, Peralta and Captain Holt must find out who it is before Deputy Chief Madeline Wuntch gets wind of the situation
Peralta and Holt repeat their Halloween wager of the previous year, but this time Peralta bets the Captain he can steal his watch before midnight and enlists criminal assistance to achieve his goal
When the squad have time to kill, Peralta launches the seventh annual Jimmy Jab Games, an eccentric series of contests held in the precinct building. Jeffords and Holt set up a new drugs task force.
Captain Holt is taken by surprise when his long-time nemesis arrives to carry out an inspection of his precinct. Peralta and Jeffords test the boundary between 'work friendship' and 'real friendship'.
Peralta's FBI operation ends in a mass arrest but he learns one mobster has escaped and enlists Boyle's help to track down the missing criminal. Holt tests the squad's patience with practice drills.