Heat Signature is the 52nd episode of Adventure Time, and the Season Finale of Season 2. It first aired on May 9, 2011.
Finn and Jake are in Red Rock Pass, Jake lowers Finn down along with himself. Finn then tells Jake he can't believe Marceline is 1000 years and has not seen "Heat Signature", and tells Jake that it would "blow their minds". Finn and Jake then run into Marceline's House. Marceline then introduces Finn and Jake to Wendy, Booboo, and Georgy, stating they use to be in a Gang in the Underworld. Finn tells them thats cool and Finn and Jake jump onto Marceline's Couch; A cracking noise is heard. Finn asks what is wrong with the couch and Jake says it Hurts his teeth. Marceline tells them that she usually floats; They kind of all do. Finn tells Marceline that it was unfair, Marceline then tells Finn that it's to bad that their not "Vampires", She then continues the conversation but Finn intterupts, telling her to wait a second. Finn and Jake then whisper to each other and then they both nod at each other, Finn the tells Marceline, "Marceline, We assist you turn us into Ghost or Vampires or Whatever, we just want to fly". Marceline Agrees and Finn and Jake high five and flip over Marceline's Couch. Wendy then complains to Marceline in Private about turning them into Ghost, Marceline tells her not to worry because she gots something more "Fun" in mind.