in its spiraling windows he sees fitful electric blue fire and hears the cries of all those pent within ; he senses both the strength of the place and the wrong-ness of it ; he can feel how it is spooling error across everything , softening the divisions between the worlds , how its potential for mischief is growing stronger even as disease weakens its truth and coherence , like a body afflicted with cancer ; this jutting arm of dark gray stone is the world 's great mystery and last awful riddle .