In this episode, Gil and Goby see a very spooky haunted house on their way to preschool and they talk to the snail who lives there. She tells them that there is going to be a haunted house party that night. Gil and Goby go tell the other Guppies and they learn all about Halloween.
The opening begins as Molly tries to say "It's time for Bubble Guppies!" However, Gil interupts by searching for her and she hides behind the clock with a scary mask. When Gil comes by, still looking she surprises him and he runs away! Then Molly says "It's time for Bubble Guppies"
Goby, Gil, and Bubble Puppy are on their way to school, when they see a haunted house. They decide to take a closer look and are surprised when the door suddenly opens. A snail and a crab with Halloween stuff make their appearance. They tell the two guppies, and puppy about the party their going to have. They are all very excited and when Goby and Gil arrive to school, Gil informs them about what happened and he suddenly spots a ghost, but nobody believes him.
At any rate, Mr. Grouper then discusses things that involve Halloween. Then the pop songplays
After the song, Oona has a cat that doesn't sound right, so she goes to the pet potions store, run by Deema. Soon they manage to find the right ingrediants to make the kitty-cat meow again and Mr. Grouper announces that it's time for lunch.
Molly is busy decorating as Gil tries to scare molly with a small toy bat. She then returns the favor, scaring him with a much bigger toy bat! She proceeds to chase him around as a ghost walks on by, nobody noticing...
The girls, Gil, and Goby are drawing Halloween related things when Nonny, dressed as a Vampire sneaks up behind Mr. Grouper and startles him! The guppies compliment him and Gil sees the ghost again! Soon everyone begins to wonder what costumes they'd like to wear for the haunted house party and soon a dance songbegins, after that Mr. Grouper tells everyone to go outside.
Molly is a zombie, a very spooky monster. She becomes scared upon seeing a spooky shadow and she runs to the spooky motel, owned by Deema. Deema gives her a room and they both enter it after managing to pick the right key for it. Once inside they see the spooky shadow has followed them! But they soon learn that the spooky shadow was really a small white mouse that was out trick or treating.
Gil tries to scare Molly again, this time pretending to be a mummy. But he accidentally scares himself when he comes across the mirror and he runs away!
Everyone heads over to the haunted house party in their costumes and they are greeted by the snail and crab. They ask the guppies to find a pumpkin for the party potion and soon they manage to quickly finish it and it makes a fashion show suddenly occur! After everyone has gone, its then a ghost appears on the runway, which shocks everyone. But when it suddenly barks, everyone then becomes highly curious as to whom it may be and Gil pulls up the sheet to see that it's Bubble Puppy!
Molly explains to the audience that there is no such thing as ghost when one appears. Molly and Gil believe its just Bubble Puppy but when it turns out it's not him they're quick to flee the scene!