I really enjoyed "This," but it wasn't an episode of THE X-FILES as generally defined. Which is to say -- the average episode of THE X-FILES has Mulder and Scully being passive investigators in a world beyond human understanding or control. "This" shows Mulder and Scully as action heroes pursuing the conspiracy to stop it rather than investigating to uncover it and they're much more combat-proficient than ever. It's at odds with the majority of other episodes.
One in-universe possibility: the onscreen events of "This" could be a simulation.
The simulated Langley tells Mulder and Scully that he exists in a world of perfection in which all his wants and desires are met, but the artificiality has become maddening for him while Erica Price declares that few if any of the digital personalities ever discover their artificial existence.
When Mulder and Scully are in the bar and narrowing down their investigation, the lighting around them darkens and dims to show them alone in shadow; neither of them react or seem to notice and it creates the sense that the world around them is a computer generated construct that's experiencing a service interruption.
There are also a number of errors throughout the episode that are clearly deliberate: Mulder refers to the National Security Agency as the NSI. Byers' headstone has a mis-spelled middle name, an error that writer/director Glen Morgan (the co-creator of the Lone Gunmen) would not make.
There is no explanation for how Langly created a cemetery based puzzle for a grave he didn't know he'd be buried in. At one point, Mulder is pretending to be handcuffed but raises his unbound hands in full view of a guard; it goes unnoticed.
The existence of a backup, unremarked upon until the final scene, is inexplicably never raised before then.
Then there's Mulder and Scully's close relationship in "This." In "My Struggle II," Mulder didn't bother to call Scully or answer her when heading off to confront the Smoking Man. Previous episodes had shown him saddened by their breakup and withholding his feelings about William from her.
But "This" shows Mulder and Scully falling asleep on the sofa together and Scully refers to Mulder's house as "our home." And then there's Mulder and Scully as seemingly invincible action stars.
Noticeably -- the conceit that the digital personalities only go online when the real person has died doesn't make sense. There is no reason why the simulation and the real-world person could not co-exist.
However, it's possible that the actual meaning is: the simulation only permits one instance of the digital personality at any given time to avoid conflicts and redundant processes, and the backups of the personalities are only activated if the current iteration is erased or otherwise ceases to function. Furthermore, the simulations may exist in sandboxed situations in multiple planes of digital reality.
Is any of "This" actually happening? Or is it a digital dreamworld in which the simulated Mulder and Scully were given an existence in which their fondest desire -- a romantic relationship with endless cases to investigate together and forever -- was granted with reality bending at the seams in order to give them what they want? The fact that William is missing and the Lone Gunmen are still dead in their perfect world indicates that their greatest wish is to be with each other without anyone else in the way -- which is selfish but human.
Moving on. "This" is an episode where Mulder and Scully are targeted by a technological phenomenon and act as action heroes in a sci-fi adventure as they go on the run from the authorities, storm the citadel of the conspiracy using subterfuge, weapons, deception and total confidence in their ability to topple any physical threat. It's strange because in the first nine seasons and two films, Mulder and Scully were hardly ever in combat situations and when they were, their attitude was generally to flee in terror from bees and choppers and tanks and gunmen.
They were regularly overpowered, beaten up, shot, pummelled, knocked out and tied up. "This" has Mulder and Scully sliding across floors, punching out assassins, shooting down enemies and Mulder, whose defining attribute in Seasons 1 - 7 was to regularly drop his gun, is suddenly a capable marksman whose uncharacteristic profiency in "My Struggle II" with defeating a thug has become the new normal.
Admittedly, there is a huge time gap between Seasons 9 and I WANT TO BELIEVE during which Mulder and Scully were fugitives and conceivably spent a lot of time retraining themselves for their lives on the run. But the structure of "This" is most unlike THE X-FILES: Mulder and Scully are the focus and the protagonists, and their abilities are well above what's been previously established.
And yet, this is actually very much in tune with how THE X-FILES worked in Seasons 1 - 9. It was a different era of TV where viewers were unlikely and unable to watch every single episode. Chris Carter, as a showrunner, rarely rewrote scripts the way modern lead producers do. Instead, his attitude was to invite each individual writer to produce their scripts from writing to airing and he encouraged each individual writer to present their unique, personal vision of THE X-FILES.
For example, Chris Carter generally writes Mulder as a stalwart hero with a meaningful purpose and mission, but Darin Morgan ("Were Monster") writes Mulder as dysfunctional and fundamentally hopeless in his goals. Chris Carter wrote aliens as unknowable, inhuman monsters of horror and madness; James Wong wrote aliens as figures of unimaginable wonder and beauty.
Vince Gilligan wrote monsters as troubled representations of the dark side of humanity which could be confronted and defeated; Chris Carter wrote monsters as beyond human understanding or control. And Chris Carter writes Mulder and Scully as passive investigators, but Glen Morgan writes them as involved action heroes. So, "This" being nothing like the other episodes of THE X-FILES is actually being quite true to THE X-FILES.
This conflicting, contradictory approach is also within Chris Carter's own episodes: he writes monster of the week episodes that are clearly set in a universe of supernatural, magical, unknowable forces, but his alien episodes are written in a universe of scientific and technological concepts in which voodoo and ghosts don't fit. His Season 1 - 9 myth-arc episodes are about aliens as a terrifying force outside humanity infiltrating our civilization and infecting it with savagery and monstrosity; his Season 10 - 11 myth-arc episodes are about humans who have co-opted the wonder and beauty of benign aliens to take advantage of humanity's weaknesses and failings. Alien colonization and the Spartan Virus are two different conspiracies; Carter treats them as the same conspiracy (aside from two lines in "My Struggle III" where the conspirator says that the aliens are not going to colonize Earth as the planet's no longer worth their while).
This is why continuity both for the myth-arc and for the characters has always been a pointless waste of time in this show. THE X-FILES was written in the 90s where episodes were written as self-directing, standalone products without much concern for what aired last week or what would air next week. This was true of both the writers and the majority of the audience and Carter has maintained this approach for Seasons 10 - 11.
Looking at "This" independently as it was meant to be seen: it's clearly about establishing Mulder and Scully as a couple with the plot being at best an afterthought, a framework to put Mulder and Scully together in every scene with the entire episode never showing them apart at all. They are a pair who are so comfortable with each other that they fall asleep on the sofa watching television, reviewing casefiles and eating junk food. They are so familiar that even as fugitives pursued by assassins, they are cheerily at ease with each other in the woods or in parking lots or in a cafe or in a restaurant or on a bus. They are so acclimated that Scully refers to Mulder's house as "home." They are so warm with each other that they can both silently decide not to bother cleaning up the house and will silently let rubbish fall to the floor and head back to the sofa where they were when the episode began.
These are not coworkers or colleagues; THE X-FILES (this week) is a love story about two people who are uniquely and intimately suited to each other to the point where their marital status and professional standing are completely irrelevant because they are a team, they are a couple, they are together and they are completely infatuated with each other and their lives. God knows what they'll be like next week, but this is what they're like in "This." It's how Glen Morgan sees them. It may not be how the other writers see them.
If you look at it from a continuity minded standpoint -- which is not how THE X-FILES was designed -- you may see an arc. In Seasons 1 - 6, Mulder and Scully went from colleagues who trusted each other to best friends and comrades to the point where even when they'd been reassigned and the X-Files office was closed or kept from them, they would investigate cases in their spare time together to the point where "Dreamland" essentially has them as a sexless couple going to Area 51 and "How the Ghosts Stole Christmas" show them spending their holidays staking out a haunted house as civilians instead of FBI agents. In Season 7, they kissed on New Year's Eve but it went no further and the Smoking Man remarked to Scully: "You'd die for Mulder, but you won't allow yourself to love him." The episode "all things" revealed that Scully had an affair with her professor in her college years that left her feeling that love was somehow a betrayal of indepedence but finally making her peace with that; the teaser and tag scene suggested that Mulder and Scully had finally consummated their relationship.
"Hollywood AD" and "Je Souhaite" showed Mulder and Scully distinctly romantic with each other, "Requiem" had Scully overjoyed to discover she was pregnant, the Season 8 finale had Scully holding her baby and Mulder kissing her and "The Truth" has them running away together. However, I WANT TO BELIEVE shows Mulder and Scully in conflict with the chemistry of a long-divorced couple reluctantly adjusted to how they'll never be rid of each other. "My Struggle I" showed them separated with Scully calling a relationship with Mulder "quite impossible" and Mulder sadly but gently saying that he and Scully had gone their separate ways "for better or for worse" while Scully said to Mulder, "I'm always happy to see you," establishing them as amicably broken up and maintaining constant contact.
However, their relationship starts to get closer. "Home Again" has Scully confiding in Mulder that she longs desperately to see William; "Founders Mutation" has Mulder claiming he has had to forget William but later revealing that he hasn't at all. "Babylon" has Scully getting over the death of her mother and then this reinvigorated Scully visits Mulder at his house and they're holding hands and walking joyfully at the end. They have only one scene together in "My Struggle II" and they have brief interaction in "My Struggle III," but "This" would suggest that after "Babylon," Mulder and Scully have become a couple again. Scully called Mulder's house "our home."
Or the next episode will resume having them living in separate dwellings and only seeing each other at the office and, retroactively, "This" was a late night work session that became movies and snacking and it was an anomaly, not a regularity. Who knows what the next episode will be? You never know what THE X-FILES is from week to week -- that's the show. It could just as easily be argued that the romantic episodes of Season 7 were simply those writers' personal visions of the Mulder/Scully relationship which exist alongside episodes in which they're platonically friendly or professionally amicable. It's almost like each episode of THE X-FILES is set in a different parallel universe.
For better or for worse, THE X-FILES is not really a series as we understand it today; it's an anthology show that features the same actors playing characters with the same names and jobs but with relationships and settings that are radically different from episode to episode and writer to writer with little to no concern for ongoing development or consistency and continuity.
"This" may be the first episode to actually silo its own episode from the rest of the series by proposing that the onscreen are all a simulation -- and it may even explain why Mulder and Scully are so different from week to week, why the conspiracy was in Seasons 1- 9 about an invasion but in Season 10 became population control without alien involvement, why THE X-FILES goes back and forth from sci-fi to supernatural -- these are all different versions of the simulation.