When fans of Brooklyn 99 were left hanging on a massive cliff at the end of season 3 they were kindly rewarded with the return of Detective Jake Peralta, Captain Raymond Holt, and the rest of the 99th precinct for season 4 - though, not quite in the traditional manner that audiences had grown to expect from the cop-comedy.
So much material happens throughout the course of the fourth season that it feels like it should be enough for more than 3 seasons worth - Jake and Holt are in Witsec while the gang leader they brought down tries to murder them, Boyle adopts a son from Latvia, Rosa almost gets married to Pimento, the precinct nearly gets shut down, and there's a season-ending cliff hanger that rivals that of season 3.
Mr. Santiago, Episode 7 (8.3)
In the Thanksgiving episode of season 4 fans are introduced to Amy's father (Jimmy Smits) for the first time when he joins the precinct for the holiday. Jake wants to impress his girlfriend's father so he creates a massive binder containing all of the information on Mr. Santiago which (of course) Mr. Santiago ends up finding. The two get roped into trying to solve one of Mr. Santiago's old cases, but it ends up being a trap for Mr. Santiago to purposely humiliate Jake. The two argue about whether Jake is good enough for Amy and in their argument they end up solving Mr. Santiago's 20-year-old case.
The Last Ride, Episode 15 (8.3)
Nobody was really worried that the 99th precinct was going to be shut down (it was only the 15th episode of the season, after all) but they gave it their best shot. When crime goes down in Brooklyn and the city decides to shut down the 99th precinct, the gang all try to find ways to spend their last day together - Terry tries to break the precinct perp record held by Hitchcock, Gina pranks everyone into drinking cement, and Jake and Charles go on one last case where they end up bringing down a high profile drug lord. Eventually the precinct finds out that they won't be shut down (thanks to Holt and Gina) and all's well that end's well.
Cop-Con, Episode 17 (8.3)
Did you know that cops have conventions? Neither did anybody else until Brooklyn 99 gave us the Cop-Con episode which followed the 99th precinct all the way to Rochester, New York where they convened with all of the other cops in the state. The detectives are excited for the notorious party that happens every year but unfortunately Holt is all business and expects the same of his subordinates.
Disobeying Holt's commands, they go to the party anyway and end up losing important information for Holt's presentation, only to have the ultimate lesson be that Holt needs to let loose and enjoy time outside of work with his precinct.
Coral Palms Part 3, Episode 3 (8.4)
The final episode of the 3-episode-arc that opened the season found the 99th precinct reunited with their beloved captain and favorite detective in Florida to help save them from Figgis, the gang-lord trying to murder the two of them. Just like how they do it in the 99 (bonus points if you understood that reference) they take down Figgis and his men and rescue Jake and Holt from their 6-month long Witsec nightmare. P.S. Don't ever get pizza in Florida if it's truly how they described it.
The Bank Job, Episode 21 (8.5)
Season 4 had several different story-arcs throughout it's entirety, but the one that had Brooklyn 99 feeling like a true-blue cop show was the finale. When Jake and Rosa accept jobs on a task force with one of their idols, Melanie Hawkins, they're ecstatic - until they find out that Hawkins is dirty and is the actual robber that her task force is investigating.
The 99 tries to bring Hawkins down but they fall right into her trap and Jake and Rosa end up getting arrested and blamed for several bank robberies. Also, find somebody who looks at you the way Pimento looks at cocaine.
The Fugitive Part 1, Episode 11 (8.5)
This two-part episode found the 99th precinct in a literal man-hunt as they tried to recapture several escaped convicts running rampant in Brooklyn. The man-hunt turns into a bet between Jake and Amy with the loser moving into the winner's apartment (spoiler: Jake lets Amy win once he realizes how much he loves her) but the situation quickly takes a turn when one of the criminals gets away. Luckily, the criminal happens to be foster brothers with a fan-favorite guest star of the show - Doug Judy!
The Fugitive Part 2, Episode 12 (8.5)
When it was revealed in the previous episode that the criminal who escaped was George Judy, fans were thrilled to see the return of the notorious Pontiac Bandit, a.k.a. Doug Judy. Even better, audiences got to see Doug and Jake partner up for the very first time (The Cruise didn't really count since Jake was tricked into it) in order to bring down Judy's foster brother. However in typical Pontiac Bandit fashion it seemed as though Jake was going to get fooled by the smooth criminal once again, only to have Judy save the day at the last minute and win himself his freedom.
Crime & Punishment, Episode 22 (8.6)
The season finale found Jake and Rosa fighting for their reputations and their freedom after Melanie Hawkins double-crossed them and set them up to be framed as bank-robbers. The entire 99 tries their best to find any evidence to help Jake and Rosa in their case, but Hawkins has an answer (or a lie) for all of their moves. A glimmer of hope emerges when Jake and Amy find a former colleague who knows about Hawkins and will speak against her at the trail, only to once again have the rug pulled out from under them when the witness is revealed to be working for Hawkins. The season ends with Jake and Rosa being found guilty and sent off to prison. Cool, cool, cool, cool, cool, cool, cool, cool, cool....
Halloween IV, Episode 5 (8.7)
For three seasons in a row the Halloween episode has missed out on IMDb's top ranking by one slot, but a steady silver medal is nothing to cry about as the fourth annual Halloween heist episode had arguably the best (and most unexpected) twist/winner of the entire series. After Jake, Holt, and Amy all won their title as an "Amazing Detective/Genius", the heist shifted to include teams and allowed anybody the chance to take home the prize - only for the entire event to be sabotaged and manipulated by the only non-cop in the entire building, Gina. She fooled everyone and even got the award renamed to "Amazing Human Being/Genius".
Moo-Moo, Episode 16 (8.9)
Despite the fact that it's a comedy (and there were still comedic moments during this episode) this is one of the most important episodes that Brooklyn 99 has ever done, and shows how the creators/writers of the show truly understand the reality of the world their show lives in. When Terry gets stopped by a beat-cop simply for being a black man walking down the street in a nice neighborhood, the show gets super real racism and how it still blatantly exists in several different ways in our society today, and also how it's not as simple as going to your superiors to fix it. The title of the episode might be innocent, but the material was about as mature as you could get.