In Accel World: Infinite Burst, a mysterious black cloud kicks Haruyuki and his friends out of the online fighting game Brain Burst. Unable to reenter, they discover that this isn’t just an isolated incident—the cloud is spreading and preventing other Burst Linkers from accelerating. Haruyuki and the others soon learn that, to protect the bond that connects them, they must confront a powerful ancient being that been sealed away since the dawn of the Accelerated World!