after she almost drowned in a lake, Madison has to live a life of fear because of it. She can't explain what happened to her while she was underwater, so she starts to have an abnormal fear of water. Madison's post-traumatic stress disorder has left her unable to function. She tries to close herself off from the world, but her fear grows and she sees a dark figure that haunts her both day and night. After Madison's friends have watched her deal with the phobia and visions for a year, they come up with an unconventional way to help her. By accident, they open a floodgate to a dark place where no one is safe. It starts pulling Madison and her friends to a place they can't get back from as they learn more about the dark history of the person who haunts them.