In Kane Parsons's feature-directorial debut, Clark (Chiwetel Ejiofor), a furniture store owner, and Mary (Renate Reinsve), his therapist, discover a dimension of seemingly endless liminal spaces accessed through the basement of the store. This science fiction psychological horror film is based on Parsons's web series and is inspired by the "Backrooms" Internet-based "creepypasta," which refers to horror-themed legends shared widely online.