Trapped in a violent, controlling relationship with a wealthy scientist, Cecilia (ELISABETH MOSS) escapes in the dead of night and disappears into hiding. But when her abusive ex suddenly dies, Cecilia suspects his death was a hoax. As a series of eerie coincidences turns lethal, threatening the lives of those she loves, Cecilia's sanity begins to unravel while she desperately tries to prove she is being hunted by someone nobody can see.