I see David Duchovny's face briefly. Then he suddenly has his arm around my neck, yanks me in his direction and points a gun at my head. He yells something at some other people that I couldn't see and drags me into this doorway. He pulls me in further and further into this dark hallway of some building.
I see nothing but black, but I hear Gillian's voice outside mumble, "It's Mulder, he's gone nuts and he has a hostage...". So I thought I was in the X-Files reality and this was Mulder who was pointing a gun at my head and not David Duchovny.
I really got scared at this point and started to cry. My eyes had also started to adjust to the dark and we were in the backstage hallways of an empty auditorium. I was choking and sobbing things like, "Mulder, no! Please let me go! Mulder, let me go!". He was ignoring me.
He dragged me up to the stage from a backstage entrance. The whole place was empty, dark and smelly. There was a grand piano in the middle of the stage - not a shiny ebony polished one, it was a dingy brown wooden one with chips and cracks. He sits me down on the bench, the gun's still in his left hand, still pointed at my head, his right arm still around my neck, he sits down on my left.
Then Mulder goes, "Play me something". I sob that I can't play piano and please let me go. He gets huffing mad that I can't (or won't) play and with his right hand on my neck, he slams my head, face up, onto the keys so that there's that loud disorganized chord that you get when you hit all the notes at once. I cry harder.
He shoves his face right up against mine as if he was going to snarl some angry comment at me. I'm still crying, frightened and thinking that all this is very real and that Mulder was going to kill me.
Then, Mulder guffaws and thumps his forehead against mine, smiling and giggling... I hear "CUT!" and Mulder gets up. I hear someone say something to Mulder, to the effect of "How could you forget your line after all that?!". I'm sitting up by now, I couldn't see anything because of the tears in my eyes. I was still pretty shaken because I actually thought it was all real, but I wasn't as scared anymore.
David walks back to me, smiles to me, pats me on the back and goes, "Sorry..." and walks around in a circle chuckling gleefully like "Oh my god, I can't believe I forgot my line after all that, but that was fun". That's when I woke up.
So it occurred to me that I was an actress on the set and we were filming a scene that involved me, but *uugh*... This happened really fast, so most of the descriptions and the more analytic parts came from thinking about it after I woke up.