Chloe Carmichael hears about the endangerment of the humpback whale, which is due to Doug Dimmadome trying to make a new marine-themed restaurant by the seaside that would sell whale meat. Chloe wishes to Cosmo Cosma and Wanda Fairywinkle that the people of Dimmsdale could be closer to underwater nature. The city flies into the Pacific Ocean and everyone can now breathe underwater.The next morning, Denzel Crocker is leaving his house being nagged by his mother, when he realizes that everything is underwater. He sees SpongeBob SquarePants and Patrick Star trying to catch jellyfish, and comes to the conclusion that it was the work of Fairy God Parents! He then decides to negotiate with the sea creatures to help him catch Timmy Turner and Chloe's fairies. Crocker is able to manipulate Patrick easily, and thanks to a misunderstanding, comes to believe that his jellyfishing net can catch fairies. Crocker asks Patrick for his net and laughs evilly.
Cosmo and Wanda decide to check up on Timmy to tell him about Chloe's wish so he won't be confused. When they wake him up, he begins choking and drowning before they tell him he can breathe underwater. Timmy asks them what is going on and they tell him Chloe wished for Dimmsdale to become better acquainted with marine life. Timmy thinks this is stupid. He is about to wish for something when Crocker breaststrokes up to the Turner house's window, holding the net in his mouth. Upon seeing him, Cosmo and Wanda turn into goldfish. Cosmo comments on how they don't need a fishbowl anymore. Timmy wishes for Crocker to go away, and a current sweeps him back to Jellyfish Fields, where he is stung along the way.
Meanwhile, Dimmadome has met Sheldon Plankton, and they are planning to merge their restaurants to improve the Chum Bucket's ratings, since Plankton already owns an unconsumed backlog of chum that, prior to the merger, could have be used to improve the marine theming of Dimmadome's seaside restaurant.Crocker realizes that Timmy finds his plan obvious, so he sends SpongeBob and Patrick out to catch Cosmo and Wanda. Cosmo and Wanda are following Timmy to school, and Timmy is distracted by meeting Chloe for just long enough that Patrick, worrying that he will miss this chance to prove himself, can catch Cosmo and Wanda without Timmy and Chloe noticing. Apparently the jellyfishing net is close enough to being a butterfly net that it does work as a fairy capturing device. Patrick gives Crocker the net with the captured fairies inside, and is very proud of this, not knowing that he has just doomed both Bikini Bottom and Dimmsdale due to Crocker's plan actually progressing. Timmy and Chloe walking to school reminds SpongeBob that he similarly needs to go to work. SpongeBob says goodbye to Patrick and runs to the Krusty Krab, repeating his old catchprase to show the world that he is ready to work at the Krusty Krab.
However, when he arrives, Eugene Krabs is raving about losing money. Squidward Tentacles tells SpongeBob that the Chum Bucket is becoming more popular, which is stressing Krabs out. Squidward remarks that at least it's not as if Krabs will have SpongeBob and him spy on the Chum Bucket to see what is making it so much more attractive. Krabs snaps out of that and tells SpongeBob and Squidward that that's a brilliant idea and that they have to go spy on the Chum Bucket.