Guest stars include Doug Savant, Rebecca Wisocky, Omari Newton, Aaron Douglas, Vik Sahay, Ryan Robbins, Christine Willes, and Kacey Rohl.
Upon presenting their findings to Assistant Director Walter Skinner, Mulder and Scully are told that the case has been closed in order to placate the Department of Defense, which has ties to Goldman and Nugenics.
Observing footage of birds which flocked near the Nugenics building at the time of Sanjay's death, Mulder thinks that the noise is a frequency normally unheard by humans.
Outside, Mulder and Scully discuss the possibility that Goldman is experimenting on pregnant women for The Project, and reminisce about their son William, who remains in hiding.
Under attack by the noise – her unborn child's attempt to communicate with her telepathically – Jackie cut her uterus open with a kitchen knife; the baby escaped and was presumed dead.
Using security footage, Mulder and Scully discover that a Nugenics janitor working one floor directly beneath Sanjay reacted strangely at the precise moment of his suicide.
"Founder's Mutation" was written and directed by James Wong, making it his first directorial contribution to The X-Files since 1996's "Musings of a Cigarette Smoking Man", as well as his first writing credit since 1997's "Never Again", both of which aired as part of the show's fourth season.
[4] The episode guest stars Doug Savant, Rebecca Wisocky, Omari Newton, Aaron Douglas, Vik Sahay, Ryan Robbins, Christine Willes, and Kacey Rohl.
[9] Darren Franich of Entertainment Weekly awarded the episode a "B", arguing that "Founder's Mutation" is "fun for fans of the show" and "an improvement over the premiere".
[10] Brian Tallerico of RogerEbert.com wrote that "Founder's Mutation" "perfectly blends show mythology (including Mulder and Scully’s kid) with a modern plot".
[12] Matthew Chernov of Variety wrote that unlike the first episode, the chemistry between Mulder and Scully "seems much closer to the playful banter we're used to from the good old days" and that the script "allows Gillian Anderson to do some of the best work in the series so far".