The original 1963 version of 'Nightmare' was that exactly. It was hallucinogenic. It pulled it off really well, too. The performances of the actors involved were compelling and solid. The dialogue was thoughtful, intriguing. The Ebonites were startling yet more humane to the humans than they tend to be to each other. Ultimately, the story and its conclusion lingered in your brain afterwards. In my case, since 1963. It dropped little clues along the way that messed with the viewers mind. It was successfully frightening in many instances.
This 1998 rewrite is merely similar. How could they do a credible rewrite of one of the best original episodes? Well...it seems that they didn't try too hard. The characters are not nearly as deep or defined as they were in the original. There is nothing terribly hallucinogenic to draw you into the story or provide background into the characters. Like the original, the crew is captured while trying to deploy a device on a planet believed to be uninhabited. It wasn't and they are captured by the Ebonites to be placed in a cell. Like the original, they are taken singly from this cell and questioned. Also, like the original, distrust grows among the captives. Unlike the original, it is less than fascinating. So, as I was viewing this I was becoming disheartened. It wasn't a 'nightmare'. I was puzzled that the creators of this updated series would drop the ball on what should have lived up to the title of this episode.
But then....the ending.
It saved the episode for me and made me smile. It was a very satisfactory twist to an experiment that worked far too well. I give it a 7 because the story is good, but I feel that they could have been able to develop the characters like the original did so that each demise would feel more personal.