Belson invites the gang to a sleepover, and whoever can survive a night of pranks and scares will win Belson's game system: the Acedia 64.
The episode starts when Clarence opening his locker, then finds a invitation. It says Belson is having sleepover at his house and also says the whoever makes it through the night without getting pranked will get his Acedia 64 (currently not sold in the U.S until next year), so to RSVP with his mom on Friday night. Sumo almost doesn't want to go, because he hates Belson, but Clarence convinces him to go. Jeff thinks that it isn't going to be good.
On the night of the sleepover, Clarence, Jeff, Sumo, Brady, Emilio, his brother Memo, and Julien go to Belson's house. His mother opens the door for them politely. She says Belson will be happy to see them all they head to Belson's room, and they come into his room, Belson closes the door on his mother.
He then shows them the Acedia 64, (which Sumo states he loves it). Belson plays a game Rated I (for Insane) game called "Psychopathic Ice Cream Man". Nathan wants to play it but Belson says, "Not unless you win,", but Nathan states he probably won't win.
After getting bored, Belson's mother calls them for dinner. The guys eat the food Belson's mother made while Belson eats a cereal called "Cheesecake Puffs" which Clarence states "It's like cheesecake for breakfast,", but Belson says he likes it for dinner. Then, Brady gets pranked by a salt shaker trick while trying to put some salt onto his fries. Belson then says he can't leave his room for rest of the night, but lets him take his fries. Jeff then becomes friends with Cythina (Belson's mother).
Belson then reads a book called "GoosePimples" about a woman named Rebecca who thinks she found her Uncle Ralph, but it was a hockey-masked killer with a chainsaw which attacked her. This then scares Emilio but acts like he isn't scared then says "Whatever.". Then Belson turns off the lights. They try not to fall asleep (knowing that if they sleep, Belson will prank them). When Clarence almost falls asleep, Sumo tells him not to sleep because Belson will prank him, but Clarence falls asleep anyway.
Belson then tries to prank him, which fails. Belson then tries to prank Sumo (which he is awake) which also fails. Then, he decides to scare the rest by pretending to be the hockey-masked killer he read from his book. He then places a tape on his bed, then walks out of his room. He screams, which wakes the group. They don't find Belson, but they find his tape that says "Play Me". They then play the tape. In the video, Belson pretends that he was "kidnapped" by the hockey-masked killer from the book he read to them, before putting on a hockey mask and taking a toy chainsaw. Sumo tells them it's a prank, but they don't believe him. He again tells them it's a prank, but Clarence says they must save Belson.
The "hockey-masked killer" attacks the group, with a toy chainsaw, which scares them, except Sumo (who goes into the air ducts). Then guys then retreat to the garage. The group then freaks out, but mostly Julien. Clarence tells them it's the hockey-masked killer from his book and asks "Didn't anyone watch that video?" Sumo comes out of the ducts and then tells them there's no killer and the book was made up, and video's a fake. He also says that the "killer" was actually Belson in a mask and that they all got pranked. Nathan asks how he knows it Belson, Sumo knows becaues he stinks and thinks he just invited them here just here to be jerk to them. The guys plan to get revenge on him by pranking back.
Clarence pretends to be a girl for a diversion. The "killer" chases "Clarencess" to the cellar from the outside, but Clarence closes the door before the "killer" can get "her". Sumo then walks to the foot of the staircase to the cellar and yells, "Hey Belson! You forgot to take out the trash!" (which Belson didn't do earlier) and dumps the trash on him.
Belson then digs his way out of the trash. Clarence begins to attack the "killer" for Belson, which then reveals he was the killer. Clarence asks why he did this. Belson says the last time he had a sleepover no one came, so if he had a prize, people would come. Clarence says they still would've still come over, but the guys say they wouldn't have. Belson then laughs at the guys for all being scared, but Sumo says, "Not all of us!". He carries the Acedia for not being pranked, so Emilio says "He's the last man standing!". Belson says he likes to keep his stuff so he then attacks Clarence, Jeff and Sumo with the toy chainsaw, but the guys escape, then see Chad driving by in a car, so the guys stop him then they get in the car (with the Acedia). They drive away as Belson almost catches them. Clarence then asks them if they had a fun time. Sumo says not quite, but he like how he dumped trash on Belson and Jeff says he's happy that him and Cythina made some real progress. Clarence then tells them that Belson isn't all bad. Belson then cries of losing the Acedia while swinging the toy chainsaw over his head.
The transcript for Belson's Sleepover can be found here.