Trivia: It was because of Natalie Wood's (Karen Brace) untimely demise that the plot was rehashed at extreme variance to the original script, and to maintain continuity, Wood's sister was used as a body double. Also, the bodily "energy rejuvenation" experienced after playing the looped orgasm tape was supposed to be a major plot-point, not something shuffled off to the side.
Dr. Michael Anthony Brace: When I found her, she looked so peaceful. Why do you have to die to let go? All my life, I never needed anybody... And now, because of this thing she left me, I'm scared. For the first time in my life, I'm scared. But the thing is, I like it. I want more. You're married to a man who has a chance to take a scientific look at the scariest thing people ever have to face. I've gotta do this... gotta play that tape, and you gotta help me.
Alex Terson: Michael, I want these personal experiments stopped. You've abused your privilege as a scientist, and you've endangered your life. The thought of you playing that tape makes my skin crawl.
Dr. Michael Anthony Brace: Where is it?
Alex Terson: It's locked away where nobody will ever have it.
Dr. Michael Anthony Brace: Alex, I wanna play that tape.
Alex Terson: You didn't hear me, did you? Nobody plays that tape.