Overdrive II tells a story of the world 100 years after the Apocalypse. The Fall does not put an end to humankind, but make them stronger than ever. Robots and cyborgs are in support of humans until the rise of a dark corrupted AI, which builds its own army of robots to take over the whole world from mankind. There goes the endless shadow battle between the robotic army and a shadow legion of human ninja warriors who swear to defense their people and this world.
The world stands on the edge of an epic war. The mighty force that the Gates of Shadows released many years ago is now an ordinary power source. This shadow energy is both a tool and a weapon, but not everyone wants to keep it this way.