The X-Files/Recap/S02/E10 Red Museum

The teenagers of a small cattle-ranching town have been disappearing, only to be found stripped and wandering the nearby woods, marked with the phrase "He Is One." Local authorities suspect the Church of the Red Museum, a vegitarian cult that has recently taken up residence. When one of the teens is found dead, however, the toxicology report reveals an unknown substance - one that Scully recognizes from a certain erlenmeyer flask. Could the town be the staging ground for a sinister government experiment?

Tropes:

 * Call Back: to "The Erlenmeyer Flask"
 * Cult: The titular Red Museum
 * Hate Plague
 * No Control Group: Averted.
 * The Peeping Tom: The only person who seems to know what's actually going on.
 * Romance-Inducing Smudge
 * Slaughterhouse Fight