Blumhouse

Invited to document her genius sister's new invention–-a machine that records dreams–Kay can’t resist. How could she know her sister believes there’s something alive in dreams. Something that holds the key to the tragedy that tore them apart seven years ago. Something that can scare them to death.

On the night of May 10, 2007, three boys entered a cave in Mantawauk County, Tennessee. Only one made it out alive. The other two were found ten days later. They had been attacked by someone - or something.