Director Rodney Ascher, who delved into the numerous theories about the classic thriller The Shining in Room 237, takes on an equally horrifying subject with his new film, The Nightmare. Today we have the first trailer for this upcoming documentary, which explores the phenomenon of sleep paralysis through the eyes of eight very different people. Gravitas Ventures will release The Nightmare in theaters and on VOD formats, including iTunes, on June 5.

These eight people (and a surprisingly large number of others) often find themselves trapped between the sleeping & waking worlds, totally unable to move but aware of their surroundings while being subject to frequently disturbing sights and sounds. Strangely, despite the fact that they know nothing of one another and had never heard of sleep paralysis before it happened to them, many see similar ghostly "shadow men." Just one of many reasons people insist this is more than just a sleep disorder.

The film digs deep into not only the particulars of these eight people's uncanny experiences through elaborate, sometimes surreal dramatizations, but also explores their search to understand what they've gone through and how it's changed their lives. Have you ever known anyone who has dealt with sleep paralysis? Let us know what you have to say after checking out this new trailer below.