pieces of dark knowledge came through then : the way a darkling 's mind tasted when it was very old , as bitter as a rusty nail held under a dry tongue ; the chaos of bixby high just before the late bell rang , almost loud enough to break her mind ; the terror that with one touch , one of the clamoring minds that harassed her every daylight moment would invade and trespass on hers ; and finally the sweet onset of the blue hour , a silence so glorious , it was as if everyone in the world had been exterminated , their petty thoughts all finally extinguished .