Asked about the idea that Gillian Anderson’s Dana Scully is immortal, creator Chris Carter told The Huffington Post, “It’s certainly been suggested, but I can tell you this: Stay tuned for episode 6 (in which we will find out what happened with Scully's son, and well be "satisfied", as Carter stated).”
The theory has its roots in an episode from The X-Files’ third
season, “Clyde Bruckman’s Final Repose,” in which Peter Boyle — who
would go on to win an Emmy for Outstanding Guest Actor — plays a man
capable of discerning how people will die. When Scully asks how she’ll
meet her end, Bruckman replies, “You don’t.”
This is "X-Files," so that's probably not even that odd, right? People
say weird shiz all the time. But then, in the Season 6 episode
"Tithonus," a man who can't die takes Scully's place after she's been
shot. She lives and is thought to take on his immortality.
Then we come to the Season 6 episode "Monday." In this episode,
Mulder and Scully keep escaping their deaths because the day keeps
repeating. Many fans believe Scully's death is exactly what caused the time loop. She was not supposed to die so time reset until she survived.
Does Episode 6 finally reveal once and for all that Scully can never die? What does this mean for the "X-Files"? We'll just have to wait for Episode 6 and find out the truth.