Josh and his pals, after saving many mixed up, time-twisted worlds now find themselves in the center of the earth, in a cavern full of mushroom people. They call themselves the 'Shrooms, and Azabeth, mistakes them for a delicious treat from her planet and takes a huge bite out of one of the taller 'Shrooms, which poisons her, leaving her in a weak and disoriented state. Now it is up to Josh, Irwin, Prism, and new friend Porcini, the Italian 'Shroom, to find the cure to the mushroom disease and save Azabeth from certain death. The journey won't be easy, however, because they will face many challenges within the deep, dark caverns. Nightmare Hollow, which is off-limits to all of the 'Shrooms, is an especially dangerous part of the caverns, and just exactly where our lovable heroes must journey to. It is there that they will learn of the history of time itself and confront the most frightening foe yet...the Muncher!

The people of the planet Aeon, blessed with six suns, have never experienced night. When an archeological excavation uncovers evidence of an ancient catastrophe, all signs point towards the impending darkness of the very first Nightfall. Panic erupts as the suns slowly disappear one by one. Science struggles against superstition as the people race to comprehend the approaching Nightfall... the end of the world as they know it. Based on Isaac Asimov's classic story "Nightfall," voted "The Greatest Science-Fiction Story OF All Time."