Harley Quinn can be an incredibly frantic, impulsive character. If this show followed anyone who was an ounce less insane, I'd say the pace of this episode is all over the place, as others have said, but because it's Harley -frickin'- Quinn, I felt like I was in the driver's seat along with her the whole time for a fantastic episode.
The show has never been afraid to throw you a curveball and not once have the writers backed down from a crazy decision. All of the insanity of the first half of the season comes to a head in what feels like the midseason finale. Gordon's arc culminates as be becomes the hero his daughter inspired and the leader Gotham needs and to see him and Harley go head to head is something I never knew I needed until now. It feels like the story this season set out to tell has been told, somewhat like when Harley got into the Legion of Doom halfway through Season 1. So that begs the extremely exciting question...where do we go from here?