While going to a science museum, Billy and Mandy's schoolbus breaks down in the middle of the desert. Then, after digging for fossils, Billy, Mandy and Grim wander around and find an abandoned mine, where Billy is captured by a giant, mutant chicken. When Mandy and Grim go to rescue him, they find an underground laboratory from the days of the Cold War, where many mutant chickens were created. In the end, the mountain makes eruption, the chickens are roasted by lava, and the whole class obtains food so they don't have to resort to cannibalism. This episode might be a parody of Godzilla (1998) and Raptor Island.