141b - The Main Drain
One day in Bikini Bottom, SpongeBob wipes the grill with a sponge (made from part of his own tongue) at the Krusty Krab. He proclaims that it is freshly clean and tries to convince a customer to eat a Krabby Patty that was on the grill. When SpongeBob went back inside to cook that patty, the customer asks Squidward why he doesn't want a Krabby Patty, and he replies that he has seen what SpongeBob cleans the grill with. It goes back to SpongeBob, who is on his way to the freezer for a patty when he slips on a puddle of water. Upon closer inspection, SpongeBob observes that the flood is coming from the sink, which is clogged with water. As he is trying to figure out how to unclog the drain, Patrick comes in and slips, but because he was his normal clumsy self.
Eventually, Mr. Krabs overhears them trying to pull the drain, and stops them before they have a chance. They hear the story of the Main Drain, and Mr. Krabs tells the story. The story was that there was a plug that two kids supposedly pulled long ago that ended the world of Bikini Bottom. When they ask him where it is, he becomes nervous and tells them to go away. The two go outside and SpongeBob steps on Plankton, and then they ask him about it. He becomes nervous also and tells them to go away. SpongeBob says that he heard it from Mr. Krabs, and Plankton claims Mr. Krabs was lying. They ask him where it is and again, no results. They turn to Old Man Jenkins, but he yields no results.
Then they go on the adventure for the plug by dragging Patrick's house. Just before they pull the plug, Mr. Krabs and Plankton stop them and tell the story of how they were the ones that pulled the plug when they were younger. They explain that they lied because they didn't want SpongeBob and Patrick to look for it. Unfortunately, Patrick already pulled the plug and everything (including themselves and the Bikini Bottomites) was sucked into the drain.
Patrick then sits up in his bed, after hearing SpongeBob's story of the drain, and claiming it's the most realistic story he has ever heard, indicating everything happens on the episode was only SpongeBob's story.