The French Narrator introduces another SpongeBob SquarePants special, hosted from Encino, California as it was 100 million years ago. From his cave-house, Patchy the Pirate, in a caveman costume, is introducing prehistoric times and talking about how great they were. However, Potty, in a futuristic robot costume, appears and says that prehistoric times were ”lame” and the future is ”where it’s at.” They begin arguing over whether SpongeBob himself likes prehistory or the future better, and while working at the Krusty Krab, SpongeBob feels a disturbance, and tells Mr. Krabs that ”I’ve got the strangest feeling that somewhere a pirate and parrot are arguing about me. And, the parrot is winning.” As Patchy and Potty continue to argue, Patchy begins the SpongeBob episode. The cartoon features prehistoric versions of SpongeBob, Squidward and Patrick, named ”SpongeGar,” ”Squog,” and ”Patar,” respectively. SpongeGar, who is sleeping in his pineapple-shaped cave, is awakened by a distant herd of monstrous purple creatures, who produce a sound identical to that of SpongeBob’s alarm clock that knocks the rock on SpongeGar. SpongeGar takes his version of Gary, who is bigger than the prehistoric pineapple itself, out for a walk, and he leaves a slime trail all over Squog’s front yard. Squog comes out with one of his two clubs to complain to SpongeGar, but slips on the slime trail, sliding into Patar’s rock, awakening its occupant, and eventually crashing back into his own house. SpongeGar and Patar begin to play, and SpongeGar uses a hollow log to blow a bubble. It then starts raining, and eventually lightning strikes the log, setting it on fire. The three experiment with it, and soon realize that it can be used to cook food, and begin cooking various items with it, including flowers, the top of a mushroom, a kelp reed, a wood stick (Patar eats it), a prehistoric ancestor of Eugene H. Krabs, seaweed flowers that look similar to corn on the cob, a green plant that looks like spaghetti, rocks that take the form of popcorn, and a Krabby Patty made of sand.
Over the commercial break, Patchy and Potty continue to fight, now keeping score between the future and the past. Patchy brings in a real live caveman, but Potty brings in a futuristic robot who begins repeatedly shooting the caveman with lasers.
At the end of the day, SpongeGar, Patar and Squog are full from eating and say goodbye to each other as they head over to their homes. Suddenly, SpongeGar, Patar and Squog stop walking and they turn around, realizing that the fire is still out there. The three of them start fighting over whom will keep the fire. They continue fighting until it starts raining again and puts the fire out. SpongeGar and Patar apologize to each other for fighting, but Squog blames them for putting it out and attempts to hit them over the head. Before he can do so, however, lightning strikes him and SpongeGar and Patar cook marshmallows over his charred body.
After the episode ends, Patchy is shown sitting outside his cave, apparently having lost to Potty. However, Potty comes outside and invites him back in, where Cavey the Caveman and the Robot Android Cyborg DX-294888 do a rap called ”When Worlds Collide.” The song montage features scenes from SpongeBob B.C. and ”SB-129.” The episode ends with Potty giving Patchy a ”gift:” a Tyrannosaurus Rex, which begins chasing him as Patchy says bye to the viewers.