" I peered deeper into the mirror, searching. Who was staring back? He looked like me, he talked like me, his body moved when mine did. I swayed to the right, then left, then back to centre; the person in the mirror did the same. This was the thing that terrified me the most – more than the victim, more than the demon, more even than the dark thoughts. It was the fact that the dark thoughts were mine. That I couldn’t separate myself from evil, because most of the evil in my life came from inside my own head. "

― Dan Wells , Mr. Monster (John Cleaver, #2)