Mother Earth had long resisted the damage being done to her by the expansion of the human population. In the past, when the numbers grew too big, she sent disease, famine, or natural disasters to contain it. However, as humans became smarter, they outwitted her devices and continued to multiply, bringing chaos and untold damage to the environment. Now, she has one last trick in her bid to defy humankind - the Creatures from Below. As young Napoleon and his dog Nate are watching TV, they are suddenly aware of the monstrous roars of creatures that are focused on the destruction of all that has been created by humans. The huge ape-like beings eventually find their way to Napoleon's home, and before long, he is hiding from them as they round up all the humans and separate the children from the adults. Determined that they will not be captured, Napoleon and Nate go on the run, evading the creatures while navigating their way through a world that is being slowly choked to death by garbage, acid rain, and a rapidly decreasing ozone layer. However, are the creatures, right? Is it the fault of humans that the planet is in such a mess? Moreover, can they educate the children to make a difference before it is too late?