The thought came to me when I was fifteen and trying to sleep on New Year’s Eve. Nothing I recall had happened to incite it. I’d spent the night babysitting my younger siblings while my mother attended a party, and she returned home around one in the morning and everyone went to bed. (My parents had divorced, though they continued to quarrel as if married.) My brother was sleeping in the bunk below mine, and as I stared at the ceiling and listened to the house settle, I thought: Why don’t you go into the kitchen and get a knife and stab your family to death?