From Bad to Worse is the 13th episode in the 3rd season of Adventure Time.
When another plague of Candy Zombies arise again and Princess Bubblegum is the only one that knows the cure is zombified, Finn, Jake, Lumpy Space Princess, and Lady Rainicorn have to find the cure for this plague.
The episode starts when Finn, Jake, LSP, and Lady rainicorn run away from candy zombies into the Candy Kingdom hall. They shut the door and the windows and nailed it. Princess Bubblegum comes and tells them that it is all her fault that the infection spread.
The flashback begins, and it starts with Princess Bubblegum is in her lab with the zombie skin. Cinnamon Bun comes into her lab and states that he is hungry. Princess Bubblegum faces her back to Cinnamon Bun and he eats the zombie skin. He becomes the zombie and the flashback ends.
Princess Bubblegum has the formula to cure the zombies but she gets bitten by the zombies because she is too near to a window that is broken by the zombies. She said something to Finn before she's turned into a zombie, that sounds like "Science will do the work. Science is mahhrahh."
Finn, Jake, LSP, and Lady Rainicorn goes to the lab and each of them take a paper of PB's cure formula. They make their own version of it. After a while, they finished the cure.
Finn is the first person to pour the cure. His cure makes the zombies have wings and have the ability to fly. Starchy, who has taken a shelter somewhere high, is taken by the Pineapple Guy zombie.
Finn, Jake, LSP, and Lady go to higher floor. Lumpy Space Princess then pour the cure to the zombies together with the flask. The cure gives the zombies Gorgeous Lips. LSP really want it and she goes outside and put it at her mouth. She then get bitten by zombies and turn into one.
The only cure left is from Jake and Lady Rainicorn. They pour it to the zombies and it gave them super strength. Finn, Jake and Lady Rainicorn go to the lab to take protection from the zombies.
They enter the lab. There's a Candy Cane Guy zombie gets out of a closet. Jake pushes him back into the closet and closed it shut and uses it to block the doors along with other things. Zombies start breaking the door, and then one breaks through. Jake quickly shuts the door, and shoves the zombie in the locker with Candy Cane Guy. Jake gets bitten on his hand, and tries to not get infected by stretching his arm.
Finn is making the cure and Jake tries to try to make himself not to attack other people by going into a shower. Finn tells Lady Rainicorn to never open the door but Lady doesn't listen to him, and she lets Zombie Jake free. Zombie Jake bites Lady Rainicorn, and she also turns into zombie.
The zombies break the lab's door and all of them tries to eat Finn. Finn takes the formula and Princess Bubblegum's rat on a trolley. He dodges the zombies and gets into safety shower.
Finn closes the door and stays inside the safety shower to finish the cure but he can't do it because the reference book is outside the shower. He then talk into the rat and says that he never knew its name. The rat shows it's name and remembers what Princess Bubblegum had said before she is turned into zombie.
Finn release the rat and the rat hands over all of the ingredients to Finn. Finn pour it into a beaker and mix it. After the cure is finished, He tested it on Jake and it works but Jake is turned into zombies again.
Finn thinks for a plan so that all of the zombies is cured. The glass of the safety shower is breaking out and Finn take a drastic measure by pouring the cure onto him. The glass broke and all of the zombies bite Finn.
All of the zombies is cured. They all sorry for each other. Princess Bubblegum then announce the hero that saved them, who is Science the rat. Princess Bubblegum then tells to her subjects to rejoice.