The French narrator starts out with saying that every year Halloween is so different in many ways. Pirates, skeletons, everyone having fun. Well almost everyone!
Scene cuts to SpongeBob flipping krabby patties. Three order sheets that say "Boo!" appropriately scare SpongeBob. He screams in fright. He's about to run home but Mr. Krabs stops him. He questions SpongeBob if he wants to listen to Krabs' annual spooky story. SpongeBob initially replies with "No thanks Mr. Krabs". Then he asks him if it's a true story. Mr. Krabs responds "True as the deep blue".
SpongeBob says OK maybe just a little. Krabs says "Have a seat, me boy" and brings in a campfire.
He starts off with "every year, the Flying Dutchman descends on a pirate ship just like this one". He holds up a krabby patty. SpongeBob responds "excuse me sir, did his ship look like a krabby patty?" Krabs interrupts him saying "and he steals people's souls".
SpongeBob replies with "do souls look like pickles?" Krabs' rebuttal: "Aye as a matter of fact they do! And he puts them where you can never find them ... in his soul bag." Krabs laughs evilly.
Squidward walks behind him dressed as the Flying Dutchman. He says to SpongeBob "I've come for your pickle". SpongeBob screams again, flying all the way up to the ceiling. Mr. Krabs' response "Ah scaredypants gets easier to scare every year". (Mr. Krabs and Squidward laugh.)
SpongeBob says "Squidward!" Mr. Krabs says "Hope you're not too scared to come to me party tonight SpongeBob scaredypants". (Krabs laughs more.) Squidward appears behind SpongeBob saying "I'll steal your soul". SpongeBob then screams out of the restaurant.
Mrs. Puff approaches him in a witches broom type car. She hits the car horn and SpongeBob screams, grabbing onto a lamp post above him. Mrs. Puff says "Happy Halloween scaredypants" (laughs maniacally).
"The name's SquarePants, it's SquarePants!" SpongeBob says.
Scene cuts to SpongeBob in this giant pumpkin, Gary is there as well. SpongeBob questions why every Halloween everybody scares him, well he's sick of it. He screams again. Little does SpongeBob know, it's only Patrick knocking on the door outside. SpongeBob says "It's Patrick, I'm going to scare him, it's my turn!"
Patrick scares him by wearing a Groucho Marx mask.
SpongeBob screams now for the 4th time, propelling him into the ceiling. Patrick says "sorry didn't mean to scare you". He then falls right side up saying "Why can't I be scary for once? When's my chance?"
Then all of a sudden 3 kids come up to SpongeBob's door and start ringing the bell. He says Rahhrr! One of the 3 kids says "Look it's the haunted mattress!" SpongeBob replies with "OK, OK, here's your candy." The kid says "No please, that was enough of a treat, thank you!"
Patrick then shows him his new paper ghost, responding "Ooh, scary!" SpongeBob says "That's it, Patrick!" Patrick responds with "what's it?" SpongeBob says "What's the difference between that ghost and me?" Patrick takes awhile saying "Don't tell me, don't tell me, I know this one, don't tell me, don't tell me! OK I give up." SpongeBob then tells him "I have a square head and a real ghost has a round one. All we have to do is make my head round and boo, I'm scary!".
Scene cuts to SpongeBob and Patrick in SpongeBob's bathroom. Patrick is holding an electric razor saying "you sure you want to do this?" SpongeBob replies with "shave me down, make me round." Patrick then says "alright here it goes!" (razor sounds)
Scene cuts to SpongeBob having a circular head.
Patrick says "Great, you're going as my trick or treat bag". SpongeBob says "No, no, I'm the ghost of the Flying Dutchman". Patrick says "something's missing. I know." He puts shoes on SpongeBob.
Scene cuts to outside in Bikini Bottom. SpongeBob and Patrick then succeed at scaring someone but they're so victorious that they forget their candy! The 3 kids from earlier come back. SpongeBob now says "Rahhrr!" again. Patrick joins in and they both run off. One of the 3 kids from earlier says "Wasnt' that the haunted mattress?" The main little kid from earlier says "I guess he's been demoted to a haunted sleeping bag!" (all 3 laugh)
Scene cuts to the Krusty Krab. A lot of things are going on. First off, we see Mr. Krabs bobbing for apples. But he ends up choking on one. Meanwhile Pearl says "Oh Dad, you're embarrassing me again." Off-screen Krabs somehow gets the apple out of his mouth and is seen flying off screen. Squidward and Sandy start to talk, questioning their costumes. Sandy tells Squidward that she is a pet goldfish in a bowl. Squidward says "I don't get it" and keeps drinking his punch. Eventually the lights shut off and everyone screams. SpongeBob lifts himself down through the Krusty Krab through a hatch door on the roof. Patrick uses a megaphone.
A jellyfish who appears to have almost real-life hands rubs them together, then stings Patrick. He screams. Eventually SpongeBob gets thrown all over the place and eventually ends up hanging upside down via a rope. One of the 3 kids notices that it's really him and Patrick uses the megaphone saying "I am not SpongeBob, these are my street clothes." The real Flying Dutchman eventually shows up to haunt everybody's souls. Just as he is about to steal SpongeBob's soul, he takes off SpongeBob's mask, then gets scared and runs off. SpongeBob laughs and says "Hey what do you know? I scared everybody!" (laughs again while everybody screams)
It is revealed that what really scared everybody was him in his brain. Patrick mistakes it for a pink hat. And SpongeBob says "That's not a hat, that's my brain." Patrick screams and the episode fades to black with SpongeBob saying "Don't worry; it grows back."