When her uncle dies suddenly, Sami is left to take care of their lighthouse alone. Coerced by their concerned parents, her step-brother Ben agrees to temporarily move in with her to help out. After years of not seeing each other, the two siblings struggle to adjust to their new situation. When they begin to notice strange footprints and objects moving on their own, they are left with only two options: Either months of isolation have driven them to their mental breaking point, or something unexplainable has begun to unfold.