With the seeming reprieve from the alien threat, Mulder and Scully move on with life and relationship. Yet dark forces continue to work in the government which may or may not be renewing an invasion.
A period of calm – With the original threat of alien invasion seemingly neutralized by at least 2008, there seems to have been a period of calm coinciding with the end of the X-Files. One would like to imagine that Mulder and Scully went on to build a blissful life together. This was true for a while but, alas, this was not to be forever. Even then, however, their work together on the X-Files was not done.
New suspicions – In 2016, Scully is asked to drag Mulder back into the world of the X-Files by an internet ‘fake news’ personality who brings a tale of government conspiracy. He seems to convince Mulder that aliens have started a new plan for invasion and partnership with shadowy government figures to facilitate it. Enough of his story ends up being true to convince both Mulder and Scully to investigate and for Skinner at the FBI to reinstate them in the X-Files.
Deep State – Mulder soon comes to believe that this plan does not involve aliens at all but rather a new shadow government of sorts, using alien technology and DNA obtained years ago, to bring about a fake invasion that will secure their total control of the world. Their plot would follow the same pattern as the original invasion plans–infecting the world with a virus that would require the activation of emergency management protocols and allow the takeover of the government. This virus would not be the original alien virus but instead a deadly and mutated anthrax-type strain to which only a few select people would have immunity. Alien technology would allow them to simulate an alien invasion, further solidifying their control as the public would react with fear and bewilderment.
The Company – While seeking to investigate this threat, Mulder also meets Mr. Y and Erika Price, heads of “The Company”, a secret corporate giant that seems to have far more control over national affairs than those actually in the government. They were once part of the Syndicate but somehow survived its destruction. They know of the coming invasion and also corroborate Mulder’s suspicion that it has nothing to do with aliens (who have actually given up interest in our polluted and climate-ruined planet) and instead is led by government secrets and CSM who amazingly survived the direct rocket blast in New Mexico. They’ve been managing their own version of the end of the world, buying time to develop space technology where a select few of humanity can start over under their control while the rest are destroyed.
Visions – Scully sees all of this happen–the spread of the virus, the arrival of seeming aliens—but it all turns out to be a vision of the future shared with her son. She comes to realize William is a central figure in this plot, either as the cure that will save humanity from the spreading virus or the contact with actual aliens. She and Mulder use the X-Files to start a desperate search for him and a way to avoid the future he has seen.
Goodbye – In the end, William does turn out to be the key–not by initiating or preventing the invasion–but rather that the pursuit of him leads to the destruction of all the leaders involved. (Caught in the cross-fire are the last remaining allies Monica Reyes and Walter Skinner, both killed by the actions of the Cigarette Smoking Man.) William seemingly allows himself to be sacrificed to stop the chance of future invasion plans and avoid a life of pursuit by government figures. We are then left with just Mulder and Scully mourning his loss on the pier–knowing the X-Files (now disgraced) will be shut down and that they will have to start life anew as a couple and miraculously (as Scully reveals) as parents as well.