In Tokyo, an impenetrable field known as "Hell's Gate" appeared ten years ago. At the same time, psychics who wield paranormal powers at the cost of their conscience also emerged. Hei is one of the most powerful of these psychic agents, and along with his blind associate, Yin, works for one of the many rival agencies vying to unlock the mysteries of Hell's Gate.
Darker than Black - An event changes the world. The night sky is now fake and the pin points of life most perceive as stars actually represent the lives of people with paranormal abilities. There are factions that want to rewrite history, and others that want to reshape the future. Hei - one of these gifted 'contractors' - and his allies are caught in the middle of something big. Can they make a difference?