The scariest moment on The X-Files didn't involve the worm that made people lash out violently at each other. Nor did it involve aliens casually abducting humans and experimenting on them. It didn't even feature the fluke/human hybrid, lurking in the sewers, crawling up through your toilet to ... well, you can figure it out.

No, the scariest moment on The X-Files involved a room full of files.

In the second episode of season three, "Paper Clip," FBI agents Fox Mulder and Dana Scully — whose job is to travel the country, investigating cases with a tinge of the paranormal — find themselves in a massive, seemingly abandoned government facility. Ostensibly on the trail of evidence that the government has been collaborating with aliens, the two discover a gigantic catacomb full of file cabinets.

In The X-Files, you are only useful to institutions as cannon fodder. Everyone else you meet is probably a monster trying to kill you.

Each and every one contains what amounts to a record of every smallpox vaccination given to every US citizen — a cataloging system, whose ends Scully and Mulder don't know but can guess at. Its mundanity only heightens its horror. In the world of The X-Files, you are only useful to institutions — whether public or private — as cannon fodder. Everyone else you meet is probably a monster trying to kill you.

This is the beauty of The X-Files, which was, among other things, a weekly horror film, an occasional comedy, a metaphorical examination of America's sins in the 20th century, an ode to paranoia, and one of the best TV shows ever made.

And now it's coming back.

The X-Files is one of the most elegantly simple TV shows ever made

At its heart, The X-Files was a cop show, built atop the detective dramas of the 1970s, where every week the unflappable gumshoe would investigate a new case, crack it, and then watch as the criminals were sent away to jail.

TV had always struggled with horror, which requires a genuine sense of peril to be successful

The X-Files took this basic setup and infused it with horror — the cases being investigated involved monsters and ghosts and extraterrestrials. Episode endings reflected the uncertainty of the 1990s: The monsters almost never entered police custody, and the characters, always in search of proof, remained forever cut off from it.

X-Files creator Chris Carter named as his greatest influence the one-season '70s series Kolchak: The Night Stalker, about a newspaper reporter whose stories kept forcing him to cross paths with monsters and other things that go bump in the night. It starred Darren McGavin, who would later appear on The X-Files (in a cheeky homage) as the agent who founded the X-Files. The series was at once a little bit clumsy and legitimately ahead of its time.

TV had always struggled with horror, which requires a genuine sense of peril to be successful — a tall order, given that television typically requires the protagonists to return (alive, doubtless) to the status quo at the end of every episode. Kolchak understood that it could introduce peril when it came to the guest stars of the week — and when it came to the main character's state of mind. The X-Files just upped the ante on both ends.

Mulder and Scully feel elemental, as if they've been airing on some out-of-the-way channel since the dawn of time

The best thing about the series was its incredibly elegant simplicity. Fox Mulder (David Duchovny) believed in paranormal phenomena — but especially in aliens, whom he was convinced abducted his younger sister when the two were children. Dana Scully (Gillian Anderson) was a skeptic, whose presence on The X-Files was meant to curb Mulder's more ridiculous theories with scientific rationalism.

And while the two remained pinned to their philosophical positions, the bond between them — first friendship, then love — was so strong as to turn them into one of TV's best dyads. It was even reflected in the actors: Duchovny all cool smolder, Anderson flickering with muted passion.

You don't need to have seen every episode of The X-Files to understand Mulder and Scully. Even their character reversals — Scully is a devoted Catholic, while Mulder is an atheist — make perfect sense. The show has a reputation for being complicated, thanks to its ongoing, overarching story about an alien colonization of Earth, but Mulder and Scully are like TV oxygen. They feel elemental, as if they've been airing on some out-of-the-way channel since the dawn of time.

The X-Files perfectly reflected its particular moment in time

The vast majority of X-Files episodes sent Mulder and Scully into the American outback in search of a monster of the week. The creatures they hunted would take forms both famous — riffs on Bigfoot and the Loch Ness monster, to say nothing of ghosts and vampires and werewolves — and obscure, like a mutant who could squeeze into any space, no matter how small.

Underneath all of these stories was a remarkably consistent framework — a local legend, known best to those who lived in its community, was slowly chased out into the open by some totem of modernity. It escaped to devour people another day, but for how long? America was changing, becoming much more interconnected. There wasn't much room left for obscure, local urban legends.

In an America before smartphones and the web, local secrets could lurk, dark shadows haunting the corners of our national psyche

It's perhaps no mistake, then, that The X-Files debuted in 1993, shortly before the internet became a major part of everyday life, and ended in 2002, after it had completely revamped and reworked everything we once knew. Mulder and Scully's frequent use of cellphones was seen as a bit of a novelty in early seasons, but by the end the technology was ubiquitous. In an America before smartphones and the web, local secrets could lurk, dark shadows haunting the corners of our national psyche. But once that increased connectivity became prevalent, a kind of shared consciousness flushed them into the open.

There's perhaps no better example of this than The X-Files' deeply scary season four classic "Home." A spooky old house on the edge of a small Pennsylvania town proves to be the center of a breeding experiment decades in the making. Family members are having children with each other, resulting in three hideously mutated brothers who will kill to protect their secret. So it has gone since the Civil War.

Yet in the '90s, the three brothers' crimes will be investigated by Mulder and Scully, modern America coming to flush them out. The trio escapes (to the strains of a cover of Johnny Mathis's "Wonderful, Wonderful"), but they can't hide forever. The world is changing, and the worst enemies evolve from local legends into national institutions.

The X-Files was also a series about where America had been and was going on a national scale. The vast majority of its alien conspiracy plot line dealt with the ramifications of things the US actually did to win World War II and the Cold War, incorporating everything from Japanese internment camps to secret experimentation on human beings to the importation of Nazi scientists to give the US a competitive edge over the Soviet Union.

The vast majority of the alien conspiracy plot line dealt with the ramifications of things the US did to win World War II and the Cold War

Many things were embellished, but not by much — and mostly because Carter tipped things over into the sci-fi notion of extragovernmental officials cooperating with alien visitors. Without those aliens, The X-Files just looks like a barely fictionalized version of US history.

Even in the alien storyline, there are tons of resonances with events that have happened in the country both during the series' run and since. Carter returned to the specter of the Oklahoma City bombing again and again, and some stories from later seasons — derided as ridiculous at the time — have more or less come true, like a massive program the government creates to spy on American citizens.

Mulder and Scully gave the show a heart. The America metaphor gave it a brain. But what gave it a soul?

The X-Files is also an anthology series like The Twilight Zone, and it can be anything in any episode

The greatest legacy of The X-Files is in its writers' room. Homeland creators Alex Gansa and Howard Gordon worked on The X-Files for a time, while Breaking Bad creator Vince Gilligan wrote for every season but the first. The early seasons saw great scripts from the writing team of Glen Morgan and James Wong (who went on to rich careers in film and TV); the later seasons saw terrific work from Jeffrey Bell (whose work is all over genre TV).

Darin Morgan very quickly realized the series' horrific tone could easily be pushed into outright comedy

The most enduring legacy comes from a writer who only penned four scripts for the original series. Darin Morgan (Glen's brother) wrote on just the series' second and third seasons, but he realized very quickly that The X-Files' horrific tone could very easily be pushed into outright comedy. That one tiny tweak opened up the show into a near anthology series, along the lines of The Twilight Zone, where every episode could have a wildly different tone from the one that preceded it.

Other writers — particularly Gilligan — tried their hand at comedic scripts. Glen Morgan and Wong came up with deep character explorations, especially of Scully. Carter filmed an entire episode in black and white and crammed it full of homages to the movie Frankenstein.

While the series' alien storyline (often called its "mythology" or "mytharc") grew more and more labyrinthine and impossible to follow, the monster-of-the-week episodes veered all over the place, a tribute to just how inventive TV could be when given free rein.

And everything was wedded to some of the most beautiful, cinematic direction around. The X-Files, inspired by the visual storytelling gauntlet thrown down by its predecessor Twin Peaks (which was fond of dreamlike imagery and normal scenes tinged with menace), turned most of its episodes into visual feasts. There were few installments that didn't feature a nearly wordless set piece, a monster attack told only in potent images. The show looked like nothing else on TV.

Mulder and Scully's quest is a fundamentally lonely one, bound to fail

The X-Files changed irrevocably in its final two seasons, when Duchovny left — temporarily at first, then permanently — and was ultimately replaced by Robert Patrick as the more traditional police drama hero John Doggett. (In the final season, he would be joined by the more faith-driven Monica Reyes, played by Annabeth Gish.) Yet the show never stopped wildly experimenting with the very format of TV itself, even if the quality became more hit or miss.

For many fans, however, the show at its finest comes down to those four episodes written by Darin Morgan. He didn't just realize The X-Files could be a comedy; he also saw how deeply sad its core was. Mulder and Scully's quest is a fundamentally lonely one, bound to fail. In his season three episodes "Clyde Bruckman's Final Repose" and "Jose Chung's From Outer Space" — both masterpieces — he pushed network television about as far as it would go, rubbing up against the outer limits of the show's two main characters.

And, indeed, if there's one reason to anticipate the The X-Files' return for a six-episode miniseries, it's in the fact that Darin Morgan returned to write a fifth script. The episode that was produced as a result (the third) is a clear highlight of the new season, to the degree that even if every episode except his was utterly terrible, the new season might still be worthwhile.

If you're only ever going to watch one episode of The X-Files, start with this season one classic

If you've never seen The X-Files, you don't need to catch up on all 201 episodes (and two feature films!) before checking out the new miniseries. The show's near-anthology status means it's generally easy to just dive in and start watching.

Plus, the new miniseries has rebooted The X-Files' mythology by stripping it down to its essence — humans and aliens collaborating on something — and removing a lot of the extraneous material (bees! super soldiers! the Bible!) that made the show hard to follow in its later seasons. The reboot isn't entirely successful, but paring things down was probably necessary.

If you've never seen The X-Files, you don't need to catch up on all 201 episodes. Just watch this one.

Regardless, if you have time to watch just one hour of the original series (readily available on all major streaming platforms), I would recommend season one's "Ice," the episode that first solidified the Mulder and Scully dynamic as it would stand for many more seasons to come.

The pair, still settling into their new partnership, are dispatched to an outpost above the Arctic Circle. The scientists cooped up there are turning on each other, due to the presence of an alien parasite they dug out of the ice.

Yes, it's a baldfaced rip-off of the movie The Thing, but it's a good one. What's more, it really gets you to invest in its guest stars — one of them a young Felicity Huffman — and reveals just how perfectly the Mulder and Scully pairing will play out in the seasons to come. The two of them might seem to be working at cross-purposes, but really they're both after the same thing: the truth. And in that shared quest, a great TV relationship is born.

The new miniseries is worth watching — but the premiere is a mess

There's lots to recommend about the new miniseries, of which I've seen three episodes. All three feature some gorgeous, eerie images — an alien's hand pressed against the glass of its downed UFO; a hall lined with children in cells, the products of horrible experimentation — and both Duchovny and Anderson quickly find their way back into their most beloved roles.

Rating 3.5

Unfortunately, however, the first episode is a total mess. Carter, who wrote and directed, wants to simplify The X-Files' mythology, but he's not particularly able to do so in a way that makes any sense. He can never give Mulder a believable motivation for just how gullible he seems to be throughout the hour, even when he's got a good potential reason in the fact that the alien colonization predicted for 2012 never arrived — a non-event that would surely have shaken Mulder's core beliefs.

Yet there's still much to like here, particularly in the solidly scary second episode and Darin Morgan's third episode. It's especially fascinating to watch the series grapple with the idea of its characters living among the detritus of its old mythology. The X-Files now has to live with the ghost of the old X-Files right alongside it, just as the US lives in the wreckage of decisions made decades ago.

This is not The X-Files at its best, but it is The X-Files at its most pure

The series, then, has returned at roughly the level of its seventh season, where the mythology seems aimless and unable to find a new purpose but the monster-of-the-week episodes can be a lot of fun. And in the now-weathered (though gorgeous) faces of Duchovny and Anderson, it's found an unintentional comment on the way the dual quests of Mulder and Scully have completely worn away whatever support system the two have other than each other.

This is not The X-Files at its best, but it is The X-Files at its most pure — two people, driven by a kind of chaste, courtly love that they would rather not acknowledge, disappearing into the darkest corners of a country that would rather not have its darkest corners explored. They hold flashlights, hoping that might be enough.

The X-Files returns Sunday, January 24, at roughly 9 pm Eastern on Fox. (It will air after the NFC Championship game ends.) It will then air new episodes on Mondays at 8 pm Eastern, beginning January 25. Previous seasons are available on Netflix, Hulu, and Amazon.