Brian found himself sitting in a very large room with a solitary light shining from behind him. He hears a voice say, "don't move." Brian stays still. The voice starts again, "tell me why you're here or I'll kill your friend." In front of him, Brian sees a familiar face, and behind her he sees the man whose voice he heard. The man is wearing armor which makes him seem larger than life, and he is holding a gun that looks like it weighs a ton. Brian says nothing, and the man again says, "tell me why you're here or I'll kill your friend." Brian remains silent as the man shoots the person who Brian had known for so many years. Brian seems unaffected by what just happened. He sits for about an hour in silence, motionless, until the light behind him goes dim. At that moment he calmly gets up, and leaves the room.
The next day he tells his friends and coworkers what happened, but nobody ever contacts the police about the murder. Why?
He's seeing a film at a cinema, and the familiar face is the one of an actress.
watching a film in a cinema. The solitary light is the projector. It goes dim at the end of the film.
Another wild angle of it is - to say
Brian is under hallucination/s, as usual, of which his friends/conacts/people around him are well aware of.
The red flag is that the man has unrealistic equipment. Brian might have fallen asleep, but noticed the flaw in the dream as he's a lucid dreamer.