A group of former military elites set out to explore an uncharted abyss, not knowing their worst nightmare is waiting for them deep beneath the ground.

Three friends - Adrian, Charlotte and Viktor - head out into the Norwegian wilderness to explore a cave. They are all experienced at this sort of thing and have planned well. Relationship issues - Charlotte is with Adrian but she and Viktor used to be a couple and he still has feelings for her - complicate the expedition, and someone seems to be following them, even in the cave.—grantss