Mulder fights to prove that a discovery frozen in the mountains of Canada is an irrefutable evidence of alien life, but his quest for the truth only leads to more lies and an unthinkable conclusion.

Scully helps Mulder fake his own death in order for him to go undetected through the Department of Defence and find out the answers to his new questions about the government hoax concerning the existence of extraterrestrial life. Meanwhile, at a joint FBI/DOD inquiry, Scully's attempt to drive out the Conspiracy's informant is halted as her cancer takes a bad turn.

The Cigarette-Smoking Man helps Mulder to obtain Scully's cure and also lets him see his real sister who doesn't turn out to be as happy to see Mulder as he would've liked. In return for this, the Cigarette-Smoking Man asks that Mulder quit the FBI and work for him in the Syndicate where he could have power and respect which Mulder turns down, deciding to stay on the side of justice. While Scully's cure appears to have worked, the Cigarette-Smoking Man faces his own enemies and disappears, presumed dead.

While Scully travels to Africa to piece together the meaning of the symbols on the spaceship beached on the Ivory Coast, Mulder is imprisoned by his own frenetic brain activity. He manages to get a message to Skinner who finds Kritschgau, and together they try to understand what is happening to Mulder before it is too late.

Scully frantically searches for a way to help her ailing partner without having anyone to turn to for help, while a catatonic Mulder's dreams lead him away from his mission and the X-Files to a place which he believes is a better life.