Director: Kim Manners
In Kazakhstan, a young boy Dmitri is witness to a mass murder in the woods. The boy is picked up by Krycek and a group of Russian soldiers who confront Martia Covarrubias who is leading a UN investigation of the incident. Back in the US, Mulder attends a lecture about Patient X, who claims to be an alien abductee. He disagrees with the other delegates, arguing that the 'little green men' stories are a cover up to hide the truth about the government developing biological warfare.
After the lecture he is approached by Dr. Werber, whose patient Cassandra Spender is Patient X. He takes Mulder to meet with Cassandra, she explains to a doubtful Mulder that aliens are on earth to deliver a message. Marita Covarrubias briefs the Syndicate on the Kazakhstan incident, telling them that it was aimed at them. Krycek calls the Well Manicured Man and offers to trade Dmitri in return for all the Syndicate's information on a vaccine for the Black Oil.
Agent Spender, Cassandra's son warns them off the case but Scully meets Cassandra, who has an implant like Scully's in the base of her neck and believes her story. Cassandra tells Scully that some nights she wakes up with a feeling she should be somewhere. After a similar mass murder to the one in Kazakhstan occurs in the US, Scully feels strongly that it has something to do with her own abduction. Later Scully has an attack like Cassandra described and finds herself on a bridge with a crowd of people as a bright light appears overhead.
This is also the first appearance of Cassandra Spender, played by Veronica Cartwright. She would later return in the Season 6 two-parter "Two Fathers/One Son". Veronica Cartwright was nominated for an Emmy award in 1998 for her performance as Cassandra Spender.
Nicholas Lea is now credited under the "Also Starring" heading.
The shot of Krycek's ship in New York Harbour is a reused shot of the ship in Season 2's ''Dod Kalm'' with a cut out of the New York skyline superimposed in the background.
In Season 2's ''Ascension'', Skyland Mountain was a private ski resort, yet here we are told it is a national park.
Scully: Shouldn't that be my picture next to that headline? Or is that you just having a little fun?
Mulder: Do I LOOK like I'm having fun, Scully?
Scully: You look constipated, actually.
Mulder: That would make sense. I've had my head up my rear end for the last five years.
Mulder: You know? You... you try to reveal what's hidden, you try to incite people with the facts, but they'd rather believe some insane nonsense, refusing to believe what our government is capable of.
Scully: You've come a long way, Mulder.
Mulder: Yeah, and still nobody believes me.
Mulder: One more anal-probing, gyro-pyro levitating ectoplasm alien anti-matter story and I'm gonna take out my gun and shoot somebody.
Scully: Well... I guess I'm done here. You seem to have invalidated your own work. Have a nice life!
Highlights from ''Patient X''
Episode Number: 110
Season Number: 5
First Aired: Sunday, March 1, 1998
Production Code: 5X13