Ever been caught in between slumber and awakening without the ability to move? If you’re like us, you probably figured it was the excessive boozing and the burrito popping of the night before working your body towards a paralyzing stroke. But, what if more sinister forces were at play?

Sleep paralysis afflicts many people, a large number of which report seeing frightening figures looming over them or even sitting on them as it happens. This horrifying phenomenon is the subject of Rodney Ascher’s The Nightmare, a documentary-horror film following eight people’s experiences with sleep paralysis.

The Nightmare will have its world premiere at next month’s Sundance Film Festival.

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