"The Pine Bluff Variant" is the eighteenth episode of the fifth season of the American science fiction television series "The X-Files". It was written by John Shiban and directed by Rob Bowman. The episode aired in the United States on May 3, 1998 on the Fox network. The episode is a "Monster-of-the-Week" story, a stand-alone plot which is unconnected to the series' wider mythology, or fictional history. "The Pine Bluff Variant" received a Nielsen household rating of 11.4 and was watched by 18.24 million viewers in its initial broadcast. It received largely positive reviews from television critics as well as fans on the internet.