Experienced by millions as supernatural assault, isolated sleep paralysis (ISP) feels like being awake and aware in bed as someone - or something - holds you down. These sensations are sometimes accompanied by frightening and realistic hallucinations. In this book these encounters with ghosts, vampires - and even succubi - are honored afresh from the perspective of contemporary dream science. Although terrifying, ISP visions can also be a reliable portal to other extraordinary states, including lucid dreaming, out-of-body experiences and otherworldly journeys.