Was watching it on Sci-Fi today and it was the one with the people who were being told to kill by various machines. Just the way the episode ended with nothing truly being solved (just averting the imminent danger). There's a sense of creepiness in the fact that experimenting is going on in the populace and they've completed their directive... whatever it was (Mulder seeing the final message "All done.....Bye Bye"). I love it.
The episode is from Season 2: Episode Name: Blood
