 I met a chatty middle-aged Latino man, JR. NPR is using his initials because he uses illegal drugs. JR said he wanted to show me a method he has for smoking crack without overdosing. I followed him around the corner to an empty stairwell. He put a crumb of crack the size of a lentil in his glass pipe. He flicked his lighter and held the flame underneath. When you do this, when you see that just melt, and you see this mold, just melt.