A missing astronaut sets her family on a frantic hunt for answers. But the more they uncover, the greater the threat becomes to them — and the world.

Expecting mother Maria uncovers chilling truths about her reclusive father-in-law's home. A sinister family secret lurks in the basement as she fights unseen entities through a nightmarish ordeal.

Following a partner swap experiment — with a "no sex" rule — four friends reunite at a beach house to face the unexpected fallout together.