Flapjack, Captain K'nuckles, and Bubbie journey to the Bottom of the World to retrieve K'nuckles' lost "sittin' muscle" (his bottom), which he replaced with a wooden belt. They go to the peak of a mountain, where his sitting muscle is located. Flapjack and K'nuckles find his sitting muscle frozen in ice, and are unable to get it out. Upset that he might freeze to death, K'nuckles gets depressed. Flapjack tries to make K'nuckles feel better by hugging him, but the heat from his hug makes K'nuckles' sitting muscle thaw out. K'nuckles puts on his sitting muscle and Flapjack and K'nuckles slide down the mountain. But the friction from the slide causes K'nuckles' sitting muscle to be burned off, and Flapjack and K'nuckles are frozen in ice.