A group of friends go to the desert for a gun instruction course and accidentally unleash a power so great it overwhelms them where they must choose between family and friends versus the fate of the world.

Three ghost-hunting high-schoolers visit the Moore House in Villisca, Iowa—the site of one of America’s most grisly unsolved mass murders. After their private tour is interrupted, the group sneaks back in at night, unaware of the otherworldly terror that awaits them.