Continuing right where "Incendium" left off, Finn attempts to act on his newfound crush for the Fire Princess, but things get difficult due to her being evil and... well, constantly on fire...
- Always Save the Girl: Finn gets this mentality. When Flame Princess sets the goblin kingdom on fire, Finn is hesitant to stop it because extinguishing any of Flame Princess's flames hurts her. Finn stops Jake's and NEPTR's attempts to extinguish the flames because he still likes Flame Princess.
- Attack of the 50-Foot Whatever: Flame Princess is able to grow huge.
- Bittersweet Ending: Finn and Jake save the Goblins but the former fails to date Flame Princess.
- Blessed with Suck: It's revealed that Flame Princess's flames are connected to her. Putting one of them out, or even one of them getting hit by a teardrop, causes her pain.
- The Bus Came Back:
- NEPTR reappears for the first time since the first season, having been playing hide and seek for fifteen months after Finn and Jake forgot about him.
- Also, the goblin kingdom from "The Silent King".
- Gadgeteer Genius: NEPTR is capable of building Humongous Mecha out of the junk Finn and Jake had lying around.
- Multi-Part Episode: The second part of "Incendium".
- Single Tear: Flame Princess sheds one after she becomes monstrous.
- Troll: At the end, Jake claims all the goblins are dead to mess with Finn. They're actually all okay.