" Kusanagi had met plenty of good, admirable people who’d been turned into murderers by circumstance. There was something about them he always seemed to sense, an aura that they shared. Somehow, their transgression freed them from the confines of a mortal existence, allowing them to perceive the great truths of the universe. At the same time, it meant they had one foot in forbidden territory. They straddled the line between sanity and madness. "

― Keigo Higashino , The Devotion of Suspect X (Detective Galileo #1)