I was born in 1965, and actually did not see Star Trek for the first time until I was ten years old and it was in reruns. One would never think of Star Trek as a scary show, and this episode has been panned by most critics. But it scared the crap out of me. The garbled speech made by the victims of the Zetars is probably a source of amusement for most, but to me it was the stuff of nightmares. My brother knew this and would try to imitate it to get a rise out of me. As well, like Dr. McCoy, I found the scene where they teleported into darkness on Memory Alpha unnerving.
I’ve always found the idea of having one’s mind taken over frightening. I was raised Catholic, so the concept of demon possession was very real to me. However, although I can’t watch The Exorcist alone in darkness, I could still watch it alone with the lights on. I can’t watch “The Lights of Zetar” alone at all, and I’m now almost fifty years old!
I think what makes “The Lights of Zetar” so intensely terrifying, even as opposed to the concept of demon possession, is that they destroy the ability of the victim’s brain to function at all. Once the demon vacates the host, the brain is still intact. Not so with the Lights of Zetar. They blow out every circuit. Their attack is comparable with a deadly stroke or seizure, something that none of us wants to think about. You can’t hide behind a strong door or shield and you can’t run away in your ship. If they want you, they’ll get you.
It’s a funny thing: I saw Alien with my father (rest in peace) when I was fourteen years old, and even though sometimes if I enter a dark room I swear I can see those things in the shadows, nothing has scared me quite as much as one unpopular episode of a 1960’s TV show which generally was anything but scary.