After making bubbles with hot sauce, SpongeBob and Patrick accidentally destroy Sandy's air supply by causing a fire and fill her Treedome with water by contaminating it. They must help her find enough oxygen in order to help them breath. In the end, SpongeBob goes to the surface to create a giant air-filled bubble, and puts it into the Treedome.

Sandy introduces Fuzzy Acorns, "the greatest karate master ever", to SpongeBob. The master is training Sandy to earn the "blacker belt", the highest belt in karate. SpongeBob wishes he had a belt, which Fuzzy overhears and tells SpongeBob that if he wants one, he has to earn it. Fuzzy offers to train SpongeBob so that he can earn the belt, which he reluctantly accepts.