Ronnie Anne forgoes a family Halloween tradition for a cool party, but learns cool doesn't always mean fun.
Today is Halloween, and Ronnie Anne and Sid are ecstatic that they got invited to a party by a 6th grader named Kingston. However, Ronnie Anne realizes that this will cause her to forgo a Halloween tradition by Bobby, where they put up a haunted house and do a dance together as vampires. Ronnie Anne asks Bobby is she can skip out on tradition, and Bobby agrees, saying that she should make the best of her first Halloween in the city, as well as saying that he has Carl and CJ helping him decorate the mercado.
Ronnie Anne and Sid head to the party dressed as a gumball machine and a lobster respectively. However, when they get to the party, it turns out that no one else is wearing a costume, as Kingston states they're all too old for costumes. To make matters worse, Ronnie Anne and Sid's attempts to act as cool creates a mess that ends up ruining the party. To avoid being humiliated even further, the girls decide to leave. Meanwhile, at the mercado, Bobby attempts to teach Carl and CJ the vampire boogie, but with little success.
While walking through the city, Ronnie Anne bemoans on how terrible that party went, and decides to call up Sammer to see what he's up to. It turns out that Sameer is hosting a party at the skate park. Believing that it's a not a costume party, Ronnie Anne and Sid proceed to toss their costumes in the dump. The girls arrive to the skate park, but the bouncer stops them, saying they need a costume to enter. They attempt to say that the turtlenecks and leggings they're wearing make them mimes, but the bouncer still refuses. Realizing they have no other choice, the girls fish their costumes out of the dumpster and decide to wear them, regardless of their smell and beat up states. They arrive back to the party, and the bouncer reluctantly lets them in. However, not long after they enter, Sid begins to feel something in her costume, and it's revealed to be a rat. This causes Ronnie Anne and Sid to fall into the half pipe and fly upwards, and fall back down, destroying their costumes, and making the bouncer kick them out (except for the rat).
As Ronnie Anne and Sid bemoan how horrible their Halloween went, they arrive back to the mercado, where they learn that the haunted mercado was a success. When Bobby asks the girls how their night went, they state that it was a failure, because of all the setbacks they hit. This makes Ronnie Anne admit that they would've had more fun if they stuck to tradition, but Bobby appreciates that at least she does something different. He also reveals that they haven't done the vampire boogie yet, and the girls decide to join in. Bobby tells the others to get ready, and with a push of the button on the radio, he, Ronnie Anne, Sid, Carl and CJ begin to do the vampire boogie, which the citizens join into the festivities.