The story starts in the midst of a thunderstorm outside Finn and Jake's tree fort. Jake is telling a spooky tale about vampires, and Finn is shaken. Finn thinks he hears something at the window, and is afraid it might be vampires, but then Jake admits that story was made up. All of a sudden, the window opens, and Marceline the Vampire Queen makes her entrance. She is friendly, but scary, assuring Finn and Jake that she usually only sucks the color red out of things, rather than blood. She entertains Finn and Jake with tales of her adventures. But after that, she claims that the tree fort belongs to her, and kicks out Finn and Jake. The boy and dog go hunting for a new home, but everywhere they look, someone else already lives there. Finally they arrive at a deserted cave, and turn it into a pleasant living space. They throw a cave-warming party, and are having a fine time, when Marceline arrives and claims that the cave is hers too. Finn wants to fight her, but realizes that he doesn't have to as long as he and Jake are together - so Marceline threatens Jake. Finn fights Marceline to defend Jake, but she bites Jake, seemingly shrinking the dog to empty skin.