In the woods outside the Candy Kingdom, Jake and Lady Rainicorn are playing in the forest while Finn and Princess Bubblegum are in the Graveyard doing a science experiment aimed to bring the dead Candy People back to life. She explains that if her decorpsinator serum works, the dead of the Candy Kingdom will arise looking as young and healthy as Finn. She tests the first batch of the formula on the dead Mr. Cream Puff. The serum appears to be working and Finn is excited while Bubblegum suspects something’s wrong. Cream Puff jumps into the grand beaker containing the rest of the serum and it spills all over the other graves of the dead Candy People. The dead candy people arise, and Princess Bubblegum tells Finn that they’re not coming back to life and are still dead, concluding that her incomplete decorpsinator serum has created Candy Zombies. This situation is dire because their attraction to sugar will draw them straight to the Candy Kingdom along with the rest of the Candy People, so the two of them race back to the Kingdom to make preparations.