Chum Caverns

"Karen! I think I know how to push Krabs out of business— we'll lure customers underground with this gorgeous scenery!"

- Plankton

"Chum Caverns" is the second segment of the twenty-fourth episode of season 6, and it is paired with "Pineapple Fever." In this episode, Plankton discovers an underground cave which he uses to lure customers to his restaurant.

Characters

 * Eugene H. Krabs
 * Squidward Tentacles
 * SpongeBob SquarePants
 * Sheldon J. Plankton
 * Karen Plankton
 * Cave dwellers

Plot
Mr. Krabs is handling the service at the Krusty Krab, when he trips on a loose floorboard after entering his office. It turns out the formula is hidden under this floorboard. Plankton is watching this and uses his new discovery to try to dig underneath the Krusty Krab so he can reach the formula without being spotted by Mr. Krabs.

However, there's a rock in the way as he's digging, so he goes around it, only for his mining drill to fall into a giant underground cave. He finds this place gorgeous, and turns it into another section of the Chum Bucket in order to lure customers to his place, while also taming cave dwellers to work for him.

The Chum Caverns becomes a success, with many citizens coming to look at the caverns, including SpongeBob. Later, he comes back to the Krusty Krab with a stalagmiter and tells Mr. Krabs that he got it from the Chum Caverns.

This makes Mr. Krabs furious, so he brings his service down to the Chum Caverns to steal his customers back. Plankton gets annoyed by this and digs under Mr. Krabs, making him fall deeper into the ground. However, he has a drill of his own and the two keep digging under each other until eventually they get trapped underground.

They agree to work together if they ever get out, and 15 minutes later, SpongeBob digs them out. However, Plankton tries to obtain the formula again, only to cause a chain reaction leading to the Krusty Krab getting buried underground. Mr. Krabs realizes he can gain more profits with captive customers this way, so he starts a business underground, with Plankton replacing Squidward as cashier since he's away.