Watch VoirFilms. According to Peter Brook, all that is needed for an act of theatre to be engaged is for a man to walk across an empty space whilst someone else is watching him. Thus, an empty space becomes a bare stage. However, this raises countless questions about the relationship between reality, everyday presence and role-playing, something experimental filmmakers coming from the 1970s world of theatre dealt with in detail. Tibor Hajas explored the topic in a short experimental film made at BBS.