The episode starts out with King Neptune in his bed watching a soap opera. His wife Queen Amphitrite tells him that he's about to turn 5,000. They want to get through the days without mentioning Neptune's beast of a son, Triton. The scene cuts to the Krusty Krab. SpongeBob tells Squidward today is work-without-your-hands day. The phone then rings. SpongeBob tells Krabs it's for him. He answers it. Queen Amphitrite is on the phone and they want to have King Neptune's 5000th birthday at the Krusty Krab.
He then holds the phone in his hand chuckling "They think I was born yesterday". Amphitrite zaps the Krusty Krab. Krabs asks Amphitrite "Is Saturday night OK for you?"
In the next scene, everyone starts putting up decorations. Krabs tells Squidward to hang up decorations or balloons. Only a second later, Krabs comes back telling Squidward that the decorations will do well. Meanwhile SpongeBob is blowing up 5,000 Krabby patty balloons, one for every year Neptune has lived. Krabs decides to roll out a red carpet for King Neptune and his Queen. A nearby customer thinks it's for her but Krabs tells her no, so she asks Krabs if she can watch them eat. Krabs at first says "No", but in a thought bubble another Krabs hits Krabs with a hammer.
Eventually, Neptune and Amphitrite enter the Krusty Krab. Queen Amphitrite tells Neptune to try and forget about their son for one more day. Everything works well until SpongeBob finds a name tag with Triton's name on it. Queen Amphitrite tells them that Triton is their son, but as you can see, Neptune doesn't want to talk about it right now. Neptune then decides to tell the story about Triton. Everyone at the table dislikes the idea. So instead he uses a 35mm camera to show a video about what happened to Triton. Neptune narrates the video himself.
It states that Triton wasn't like Neptune at all. Neptune wanted Triton to take his smithing lesson. But Triton wanted to play baseball instead. Later, Triton tells Neptune that he's created a cure for all mortal diseases. Neptune is furious with his son, telling him that they are gods, so they don't have diseases. Neptune locks his son up in a cage. The movie comes to a complete stop. SpongeBob then realizes it was his fault for mentioning the name Triton. Squidward tells them that the krabby patties he cooked won't get eaten if Neptune isn't happy. SpongeBob tells Squidward that he can't handle the words Squidward is saying. So SpongeBob decides to make things right by reuniting Neptune with his son.
Cut to commercial break.
Next we see SpongeBob take a bus to a floating island in the sky. SpongeBob falls to sleep for a nap. Meanwhile back at the Krusty Krab, Neptune is inconsolable, so Squidward tries playing a tune on his clarinet, but it only makes him miss his son more. Back at the floating island, a mysterious strange toenail clipping wakes up SpongeBob. He then says he had a dream where he was hit by a toenail clipping. He then realizes he discovered some rope. He pulls down on the rope to reveal Triton in his cage. Triton and SpongeBob talk for a little while. Then SpongeBob tries to release Triton from the cage, which is locked by a puzzle lock. SpoingeBob calls Patrick to come to the island and help him free Triton from the cage in the island in the sky. Patrick solves the combination lock easily. He just peels off the puzzle squares, then places them in the correct order, to be able to unlock it.
So SpongeBob, Patrick and Triton ride in a car that Triton made himself with his magic wand.This all works until Triton says "Do you mind if I stop?" SpongeBob says "What's the matter Triton, need to use the bathroom?"
Triton tells them he needs to stop to tell them he doesn't need them anymore, and drives off without them.
Meanwhile, back at the Krusty Krab, Krabs tells Squidward to try to play another clarinet melody. Squidward tries to play a note, but a car horn comes out. It is revealed that the car horn is none other than Triton, who locks King Neptune, Queen Amphitrite and the rest of the party up in a similar cage. When a customer asks Triton for an autograph, he zaps the customer.
Elsewhere, SpongeBob and Patrick have discovered that their world has been destroyed. They need to get to the Krusty Krab quick, so they take a shortcut that leads them inside the Krusty Krab grill. Eventually, Patrick comes to the rescue and frees Neptune and the rest of the party. Triton gives Neptune the best birthday present he ever had, using his god powers. They both say "I love you" to each other. Then everyone goes home.
Neptune thanks Krabs for the party and says it was all SpongeBob's doing. SpongeBob is excited until a customer says "Do you hear that? Neptune said all this is because of him". Customer 2 says "He did, did he?"
The episode ends with a chase scene when SpongeBob and Patrick go to Goofy Goobers ice cream shop and then, Krabs then looks confused. The episode ends.