Creepy Souvenir: The town of cannibals kept their victims heads in a cabinet.
The Cuckoolander Was Right: Mulder acquired a tape of a mental patient rambling on about escaping the town. To the casual observer, he doesn't make any real sense, but he keeps saying something about a horrible way to die.
Dramatic Unmask: After shooting the executioner, Mulder pulls off his mask and finds him to be Sheriff Arens.
Even Evil Has Standards: Walter Chaco, spoiler:responsible for the murder and cannibalism of at least 87 people, gives a heartfelt speech about how the town can't turn against its own members or they'd become "an abomination".
A Fęte Worse Than Death: The conspiracy of a bizarre town kills outsiders and turns it into a big celebration. The residents engage in a cannibalistic ritual borrowed from primitive tribes.
Genre Blindness: Invoked by Chaco, who says the townspeople will doom themselves the moment they begin turning on each other. No one heeds his warning.
Laser-Guided Karma: The town's latest victim manages to infect them all with Creudztfeldt–Jakob disease, thus ensuring they will eventually all die raving and hallucinating.
Mundanger: The threat in this episode is an entire town kidnapping and eating their victims. Scully almost suffers this fate. While the clan do get extended life through the ritual, it's in the background to the actual threat.
Older Than They Look: Thanks to their, err, special diet, everybody looks much younger than they actually are.
Police Are Useless: Sheriff Arens is reluctant to cooperate in Mulder and Scully's investigation and appears disinterested in the whole thing. Justified because Arens turns out to be the executioner of the town's cannibalistic rituals.