That helpless feeling in whatever situation is a primal fear for a lot of people. It's why I'm afraid to fly. My fate is in the hands of mechanics and pilots I don't know.

There was trend back in the Eighties for plots where a hospital patient witnesses a murder, but no one believes him or her because the patient was on painkillers or coming out of sedation or something. No one except the killer, of course, who works on the hospital staff and was usually a doctor. I'm sure that plot has been done at other times, but I remember a whole lot of books, TV episodes, and movies with that plot all coming out in a bunch when I was in high school.