In the wake of an unprecedented cataclysm, the air has become unbreathable and hostile creatures have taken over the planet, forcing the last remaining survivors to hunker down in a makeshift tower. Among them, a group of volunteers have been specially trained to seek out a new garden of Eden. They're known as the Rippers! During a reconnaissance mission, the Oak squad meets Junk, an optimistic young boy who doesn't seem affected by the miserable state of the Earth…