The Survivors, TNG 3
When TNG is really cookin’ it should be like Twilight Zone in Space. Here’s a good example. Actually this may be the first episode where we, the audience, has guessed the ending before its happened. This is going to recur as the show gets better and better. The mystery stuff is there and then the spaceships and lasers and strange alien powers stuff comes in, too. No synopsis on this one — see it for yourself.