How to Rock Halloween is the Halloween episode of How to Rock.
The gang plans on going Trick-Or-Treating but Kacey Simon would rather perform at the Perf party.
The members of Gravity 5 dress up as fingers for Halloween, but Kacey who was supposed to also dress up with them, comes in an old-fashion queen costume instead. This is because she found out there's a Perf party that night and the band cancelled so she thinks that Gravity 5 can rock the party. The gang decides to go Trick-Or-Treating without her.
While Kacey is trying to figure out how she can play all of the instruments herself, her costume gets caught on the drums and she falls and hits her head. When she wakes up, she's a werewolf and the rest of the band is too, while the Perfs are vampires. Molly and Grace tell Kacey and the other members of Gravity 5 that they are having a party but "No dogs allowed."
In class, their teacher is talking about "The Chosen One," and as he's saying all of the characteristics of The Chosen One, Kacey is realizing it might be her. Then, a gold beam of light shines on her and she realizes she is The Chosen One.
Kacey makes plans to go howling with Gravity 5 because it's a full moon and Halloween night. They leave, and Kacey smells a yummy steak which is sitting on a plate on the ground in the cafeteria. She tries to grab it but the plate is on a string and keeps moving her into the Perf bathroom. There, Molly and Grace ask her to play the vampire dance because she's The Chosen One.
Kacey goes back to the band and asks them to play the party with her, but they say no because they already had plans to go Trick-Or-Meating. When Kacey leaves, Zander wonders if the vampires are up to something, so they look through one of their text books and read that if a Chosen One sings a high note during a full moon on Halloween, a portal will open and demons will be released, destroying the werewolves forever.
At the vampire dance, Molly gives Kacey the lyrics to her “favorite song” that features a long high note. Zander, Nelson, Stevie, and Kevin come to the party to look for Kacey to warn her. Kacey starts singing and dancing and the gang tries to stop her during the song, but Molly and Grace keep putting mummies and zombies in their way. Kacey hits the note, and the portal opens. The other members of Gravity 5 are sucked into the portal.
All of a sudden, Kacey wakes up from her dream with the members of Gravity 5 around her. She's happy they're still alive. They say that if it was that important for her to play the party, they want to do it. But she decides they should be Trick-Or-Treating instead.
At a house, they run into Grace dressed as a ski bunny getting candy — but she's supposed to be at the Perf party. "Don't tell Molly," she says, and Nelson runs after her.