Brooklyn Nine-Nine Recap: Did Jake Finally Catch His 'White Whale'? Plus, 4 Other Callbacks From Seasons Past

The deuces were indeed wild during Thursday's back-to-back episodes of Brooklyn Nine-Nine, as Jake came face to face with the criminal mastermind he'd previously deemed his archnemesis.

In the second episode, titled "Balancing," Jake and Charles were on the hunt for Peralta's "white whale," serial killer Johnny Franzia. Amy, meanwhile, was set to pitch the Nine-Nine's new pilot program: a reimagining of how the NYPD's uniformed officers should be deployed, which was conceived in the wake of the previous episode's "Blue Flu" outbreak. (As Holt laid out for O'Sullivan, fewer uniformed officers on the street led to fewer bad arrests made, fewer complaints filed against the NYPD, and fewer cases thrown out at arraignment due to insufficient evidence.)

Amid their busy schedules, Jake and Amy needed a babysitter for Mac and conducted interviews in the interrogation room. Little did they know that among the prospective sitters was the elusive Franzia, who brought Mac a stuffed lion he'd implanted with a microphone in order to stay one step ahead of Peralta and Boyle. Boyle ultimately made the arrest without his BFF, who agreed to stay home with Mac while Amy made her big pitch to NYPD higher-ups. But as a result, Jake got to witness his son lift himself up for the first time, which was just about the most precious thing we've ever seen.

The return (and subsequent arrest) of Jake's "white whale" was one of several callbacks to previous episodes of the Fox-turned-NBC comedy, with references dating as far back as Season 2. Scroll down to see if you missed any of 'em — if available, we included video of the original scenes being referenced — then hit the comments with your thoughts on Episodes 3 and 4 of B99's victory lap.

Years ago in Coral Palms, Fla., while he and Jake were in witness protection, Holt told the detective that he has a tattoo. But to this day, Holt had yet to reveal what it is, or where it is on his body. During "Blue Flu," Holt let slip to Rosa that his vintage ink is a "tramp stamp," but the episode stopped short of revealing his body art. Jake, however, was tricked into believing that Holt's tat is a decimal point.

Thankfully, Charles didn't have testicular cancer (phew!). But that big ol' Dianne Wiest infection? Yeah, that still hasn't cleared up. ("Like yeast!!!!") When Boyle thought he was dying, Jake suggested the two of them embark on a cross-country road trip so his BFF could potentially use his hall pass to hook up with the Bullets Over Broadway star.

Because the cop comedy wisely avoided running "Hot Damn!" — one of the greatest improvisations of all. time. — into the ground, it was a delight to hear Holt utter the two-syllable phrase again, six years after he first said it, the moment he figured out how to put a stop to the "Blue Flu."

Franzia was first referenced in the penultimate Season 5 episode "White Whale," before Sleuth Sisters Amy and Rosa went off in pursuit of their own "white whale," drug lord Sergio Mindar. Jake might have felt like he spoke about Franzia constantly, but it was the first we'd heard of the serial killer.

Prior to entering her apartment, Amy celebrated the NYPD reform approval by doing her signature dork dance, last seen in Season 5 when she passed her sergeant exam.