@Quavious3
The main characters, Finn and Princess Bubblegum, try to keep the candy people unaware of the zombie threat, fearing they would panic and explode. They gather the Candy People under the pretense of a slumber party to distract them from the encroaching zombies.
This setup creates a tense situation where Finn must try to prevent the Candy Kingdom's citizens from realizing the impending doom, while also attempting to fix the situation and restore the fallen candy people to their rightful state. The episode further establishes the relationship between Finn and Jake, as well as the unique and somewhat chaotic nature of the Candy Kingdom and its inhabitants, who are literally made of candy.