He met Scully in a hospital, where he pushed her down stairs while attempting to escape. Nevertheless, he contacted her and Mulder again to tell them the truth as he understood it. He explained that the entire alien and UFO conspiracy was nothing more than an elaborate series of lies to draw attention away from sinister military experiments on an unsuspecting public. So-called "abductions" were actually careful military tests involving chemical and biological warfare, among other things. Kritschgau's son died as a result of Gulf War Syndrome, which he felt party to because of his work at the Defense Advanced Research Projects Agency and connections to a pharmaceutical company called Roush Technologies.
Following the incidents, Kritschgau was fired.
In 1999, the discovery of an alien spacecraft off the coast of Africa caused Mulder to begin experiencing intense mental trauma. While in the hospital, Mulder requested that Skinner bring in Kritschgau, who would know what to do. Kritschgau recognized Mulder's symptoms from his work in the CIA and was able to identify the correct drug to slow down Mulder's brain activity to a normal level. He then became involved in the investigation of the spacecraft symbols, having hacked into Scully's computer and downloading the images she took.
- "Gethsemane" (First appearance)
- "Redux II"
- "The Sixth Extinction"
- "The Sixth Extinction II: Amor Fati"