From the bestselling author of Cops' True Stories of the Paranormal. Up to 50% of the population has experienced sleep paralysis. They wake up in their beds to discover they can't move, not a muscle, sometimes not even their eyes. If they manage to open their mouths to scream, nothing comes out. And for many of them, the terror doesn't end there-some see something in their bedroom darkness...something moving. A human-shaped...