Season 6, Episode 15: “Arcadia”
Original Airdate: March 7, 1999
What is more terrifying than perfection? Than knowing that it exists, knowing that it is possible, knowing that you—definitely—have not yet achieved it? Who would want to be surrounded by perfection, to be entirely devoted to its pursuit? In “Arcadia,” Mulder and Scully go undercover at a creepy planned community that has had some creepy unexplained deaths and Mulder pouts. “This isn’t an X-File,” he says. “Sure it is,” says Scully. “It’s unexplained.” But no, it’s more than that. It’s perfection. It’s the eeriest, most unforgivable thing there is.