At South Park Elementary ex-Vice President Al Gore makes an appearance where he is there to educate the children about "ManBearPig," a creature that he describes as ½ bear, ½ pig and ½ man. Al Gore promises to save them from the "cereal" danger of the "ManBearPig." Later that night the boys are out playing basketball when they spot Al Gore in a "ManBearPig" outfit. On their way home Randy Marsh tells the boys to stay away from Al Gore, who is just looking for attention. After receiving a late night call from Al Gore, feeling sorry for him, Stan agrees to bring his friends to attend his "ManBearPig" meeting the next morning. At the meeting an alarm goes off, Gore's equipment shows the presence of "ManBearPig" in a cave that the boys tell him is a tourist attraction. He convinces the boys to join him on a trip to the cave to find and stop the "ManBearPig." At "The Cave of the Winds" the tour guide is giving the regular tour, while Al Gore takes the boys into another part of the cave, where he fires his guns several times and causes a cave-in. Everyone makes it out of the caves safely, except for our four boys, who might also be trapped in the cave with the "ManBearPig."
The boys call for help to no avail and they split up, looking for a way out. While Cartman is looking, he comes across a treasure chest and now he has to figure out how to get the treasure out of the cave without letting the others know about it. Rescue workers are on the scene. Al Gore tells the workers that they have an additional "cereal" problem, the "ManBearPig." The boys wonder if they'll be saved, meanwhile Cartman keeps taking a crap every ten minutes, working his scheme to get the treasure out of the cave. Al Gore is discouraged that no one will listen to his plans to kill the "ManBearPig." Cartman's plan to get the treasure out of the cave consists of him eating it. The others are worried about Cartman, when he sounds terrible and has begun putting on a lot of weight.
The boys attempt to lift Cartman out of the cave. Meanwhile, Al Gore has taken matters into his own hands and he diverts a nearby river into the cave in an attempt to drown "ManBearPig." With the threat of the water bearing down on them, the boys make a last ditch attempt to get out of the cave. When the rescuers workers declare that no one could be left alive after the unexpected flood, Al Gore celebrates a victory that only he knows (or cares) about. Kyle appears to drown with Cartman, whose extra weight is bringing them both down and keeping them from swimming effectively. Al Gore eulogizes the four unknown boys who lost their lives in the caves, while he was defeating "ManBearPig." The boys make it to the surface and Stan immediately reads Al Gore the riot act. Kyle wants Cartman taken to a hospital, but Cartman just wants to go home and rest. Cartman doesn't make it very far, when he craps treasure. He finds out the treasure is worthless ($14) and placed at the end of the cave tour as a place for kids to get their picture taken. While Cartman continues to crap treasure, Al Gore looks for another project to do where people will take him "super cereal."