It's a new day in Trollzopolis, and everyone but Ruby has awful breath from the cookies Simon fed them. Simon gloats to Snarf about how the cookies were time-delayed and will slowly turn the girls evil. On their way to school, Ruby notices her friends are acting meaner than usual, and when pressed they say they learned from her example. She's further alarmed when they use magic to create chaos in class, hypnotizing Mr. Trollheimer, and turning Coral, Opal, and Jade into puppets for their own gain. In tears and fearing she's a monster, Ruby goes to see Obsidian, who tells her that if she sets a bad example she can change it by setting a good one.
Ruby vows to clean up her act, and does so, but Amethyst and the rest are still acting mean, and they're getting even worse, turning Rock into a dog and planning to set up a circus at school later that night. Ruby goes to Obsidian once more, who reveals that she's missing some of her spell bead stock—powerful 'do-as-you're-told' beads. Ruby realizes that her friends must have stolen the beads! She and Obsidian then realize that if Simon, as Garnet, fed the four girls cookies, they couldn't get the taste of the cookies out of their mouths, and only those four are turning evil, Simon must be behind the trouble.
Ruby busts in on the circus to find the girls have hypnotized Flint, Alabaster, Jasper and Coal to do humiliating and dangerous stunts. But the main event is Simon's return! Using the stolen beads, the girls capture Obsidian, hypnotize the entire crowd, and lead the city into chanting for Simon. Only Ruby, Coal, Rock, and Mr. Trollheimer are free, and Trollzopolis itself falls under Simon's thrall...
This episode contains examples of:
- Brainwashed and Crazy: Amethyst, Sapphire, Onyx and Topaz are turned evil by Simon.
- Face–Heel Turn: Everyone but Ruby ate Simon's magic cookies, and the end result is them turning evil.
- Forced Transformation: Rock is turned into a dog.
- Messy Hair: The BFFL sans Ruby have rather messy hairdos when they turn evil.
- Mind-Control Eyes: People the evil BFFL mind-control get these when hypnotized.
