The entirety of the majestic Sky Casino is turned against the Hunting Dogs when they uncover a terror plot that will shake the very foundations of the world. Their only hope is to capture the casino's general manager, Sigma, the man without a past! Meanwhile, Atsushi and Kyouka fight from the shadows, seeking to prove the innocence of the detective agency through their actions. Can they find the all-powerful "Page" that's at the core of the Decay of the Angel's villainous plot?