Honestly, the A-plot of Peralta trying to beat the slump he's in is the least interesting of the bunch. It's a great way to demonstrate Holt's manipulation of the goofy detective, as Peralta (and we) learn to trust him more and more as a captain. And honestly, when he scornfully tells Peralta, "what did I say about using voices?," I couldn't agree more. The wry dry Holt is working, and the over-reaching Peralta is not. Even if I will refer to people in slumps as "pee-moles" from now on.
I found the situation with Santiago and Gina far more interesting. Santiago is starry-eyed and desperate to be noticed by Holt, and jumps when he assigns her to recruit narcs from the ranks of local troubled youth. 'Scuse me, I mean, precinct youth outreach blah blah blah she's making kids narcs. There is a moment where Santiago has had it seriously up to here with the kids and goes off on how terrible they are. It hit too close to home. That rant is the life of a teacher. Every. Single. Day. Kids DO suck, Santiago. You are correct, madam. Preach.
Despite Santiago dropping the truth bombs, Gina is the one who steals this story line. From her "I hate you not joking BYE" to her assertion that cops are the worst to the strange interpretive dance that she somehow unabashedly performs, her weirdness is front and center. And even though her strange speech cadence and the non-sequitur nature of her lines is sometimes off-putting, it works in this context. I'm rooting for her. I think she might be the new Kelly, a character who personality traits would make me crazy in real life, but I can't help but love her on TV.