Millennium Group consultant Frank Black (Lance Henriksen) travels to North Dakota to track down a burgeoning serial killer who has progressed from mauling horses to attacking and killing people.
"Broken World" featured the last directorial effort for the series by Kolbe, and the last script written by Moresco; however, Harbinson would return to write further episodes in later seasons.
In Williston, North Dakota, a stable-hand named Sally Dumont (Ingrid Kavelaars) is attacked and left unconscious after she finds a horse has been killed in its stall.
The Millennium Group sends consultant Frank Black (Lance Henriksen) to investigate, as twenty-one horses have been killed in the same manner over the past two years in the area.
Black consults with a veterinarian, Claudia Vaughan (Jo Anderson), and learns that the area is home to a Premarin farm—estrogen for pharmaceutical use is derived from the urine of mares which are kept pregnant, their foals killed for meat to be exported.
Black, fellow Group member Peter Watts (Terry O'Quinn) and Sheriff Falkner (John Dennis Johnston) track the kidnapped Vaughan to an equine slaughterhouse.
[4] "Broken World" also marked the final episode of Millennium helmed by director Winrich Kolbe, who had previously worked on "Lamentation", "Force Majeure" and "Kingdom Come".
VanDerWerff described the episode as "a bland, boring mess that ends with one of the most ridiculous deux ex machinas [sic] I’ve seen in ages", and felt that "the guest cast is uniformly poor", singling out Van Quattro as being "laughably bad".
[12] Robert Shearman and Lars Pearson, in their book Wanting to Believe: A Critical Guide to The X-Files, Millennium & The Lone Gunmen, rated "Broken World" three stars out of five, finding it "too familiar and too tentative to make much impact".