Bio: Michael Kritschgau, appears in Gethsemane, telling Mulder that he was just a pawn in a government hoax about extraterrestrial life. Telling him that he was just used to perpetuate a plan, Kritschgau destroys Mulder's whole belief system. An employee of the Defense Department, Kritschgau had been disguising information for years.

He claimed that the government's purpose in perpetuating the myth of UFOs and aliens was to cover up its own misdeeds after he Second World War. His employment by a biotechnology company called Roush, a front company for the Consoritum, raises some questions about his motives as well. He says he is helping Mulder out of guilt for his own son's Gulf War illness and the belief that the government had destroyed his life. His son dies shortly afterwards. He does help Mulder find a cure for Scully's cancer (Redux) but stops aiding him after he is found out and fired.
He then reluctantly comes to Mulder's aid on Skinner's secret insistence when he is in a Washington hospital in an undiagnosible state(Sixth Extinction). Together with Skinner he conducts a battery of tests on Mulder injecting him with chemicals to make him more responsive. He comes to the conclusion that the alien virus injected in Mulder years earlier had been activated and believes that Scully's research can prove that Mulder had biologically become an alien. When she refuses to share her research, he hacks into her computer resulting not only in his death at the hands of Krycek but also the destruction of the research.