For over a century, this farm family has lived on the outskirts of town...and the outskirts of civilization. Generations of inbreeding have deformed their bodies and their souls into something less than human, and more than animal. Now that the family has dwindled down to three brothers, Mulder and Scully suspect that the Peacocks have devised a grotesque plan to propagate their species...by forcing a kidnapped woman into involuntary pregnancy.

While someone (or something) watches unseen, Mulder and Scully explore the Peacock farm and find the bloody evidence of a recent birth. Before they can arrest the Peacocks, the family strikes back. Later that night, the Peacock boys massacre the sheriff and his wife. As Mulder says, "They went caveman."

Fearing for the life of the Peacocks' prisoner, Scully and Mulder courageously invade the farmhouse with only the local deputy as back-up. When they discover the hiding place of the clan matriarch, they finally comprehend the appalling truth. Mrs. Peacock, a multiple amputee, is the mother of the murdered infant. And also the proud mother of three sons who'll do anything for mom.

With guile, luck, and firepower, Mulder and Scully manage to kill two of the rampaging Peacocks. In the confusion, the oldest boy and Mrs. Peacock escape in their long white Cadillac. Mother and son drive off in search of a new place to call Home.