After becoming TV celebrities, a team of ghost hunters is assigned a new job investigating a house haunted by the evil spirit of a serial killer, but the gig soon turns into an actual haunting with a demon trying to possess their bodies.
While diving in a remote French lake, a couple of YouTubers who specialise in underwater exploration videos discover a house submerged in the deep waters. What was initially a unique finding soon turns into a nightmare when they discover that the house was the scene of atrocious crimes. Trapped, with their oxygen reserves falling dangerously, they realise the worst is yet to come: they are not alone in the house.