Three episodes from the landmark television series will screen as part of the fourth annual Hero Complex Film Festival.

PERSPECTIVE

I came to “The X-Files,” which turns 20 this year, after its first season, and for a time I had no idea what was happening. This was a good way to watch a show whose greatest strength was its air of dreamlike mystery.

Folded across the turn of the 21st-century, it was a millennial show for a millennial time, reflecting a popular preoccupation with apocalypse and messiahs, puzzling phenomena and unexplained mysteries, psychic surgeons and alien autopsies, random mutations and science gone too far. It was also, looking back on old episodes, a time of pay phones, answering machines, tape recorders, dot-matrix printouts, padded shoulders and big eyeglasses.

The basics were fairly clear: Fox “Spooky” Mulder (David Duchovny) and Dr. Dana Scully (Gillian Anderson) were FBI agents whose particular job it was to handle cases outside the bounds of conventional human crime — paranormal this and that. He was (mostly) a believer and she was (largely) a skeptic, which gave them something to disagree on.

Their superiors, some of whom were also villains, were not happy about their work, but for some reason — possibly there was a reason, which I have since forgotten, other than that there was a TV show to make — they mostly let it go on.

“Again, nothing but evidence,” Mulder says at the end of another hour in which they have discovered much and proved nothing, “and again ,no evidence at all.”

Between the “monster-of-the-week” episodes, the show also established a complicated ongoing story founded on Mulder’s search for his missing sister, whom he believed to have been abducted by aliens when they were children. This eventually worked itself out into a relatively neat intertwining of alien-colonization and government conspiracy stories.

Yet I preferred to not quite follow this “mythology,” to keep it a little out of focus. In the realm of the fantastic, you are always better off with questions than with answers, which even when they are supernatural are by their nature prosaic. And though creator Chris Carter and story editor Frank Spotnitz made sure there were more of the former, the truth, in the words of the series’ tagline, was better kept “out there,” a little beyond our grasp — just as Mulder’s “wanting to believe” was more interesting than any confirmation of his hopeful belief.

Characters such as William B. Davis’ Cigarette-Smoking Man were less interesting the more I knew about their motives, even if there was always something new and unsuspected (and sometimes seemingly arbitrary) to learn.

Indeed, similar plots and plotters have been recycled through countless films and television series, some of which took inspiration directly from “The X-Files” and few of which have had anything like that series’ allure, intelligence or impact.

I don’t know how much direct inspiration Carter took from “Twin Peaks,” whose two-season run ended the year before “The X-Files” began. (The mid-’70s “Kolchak: The Night Stalker,” with Darren McGavin as a reporter weekly engaging the supernatural, is its most frequently mentioned influence.) But the two have much in common: woodsy, murky Pacific northwest locations (“The X-Files” filmed in and around Vancouver for its first five seasons, and “Twin Peaks” filmed in Washington state); mysterious, sometimes nameless characters; and a deep investment in the notion that there is meaning in a beautiful image.

Even more than “Twin Peaks,” “The X-Files” explored mood as content. Though it was born in the age of the 4:3 aspect ratio and (comparatively) low-resolution image, there was from the beginning an intentional, emotional, painterly use of color and shape and a choreographic approach to light. You can watch the show with the sound down and still feel what you are meant to feel.

At the same time, there were occasional flashes of meta-fictional self-consciousness: “Where’s the writer? I want to speak to the writer,” a dissatisfied Mulder says at the end of “The Post-Modern Prometheus,” which was shot, in shadowy black-and-white, like an old Universal Pictures “Frankenstein” — and framed as a comic book, for good measure.

In the Season 3 episode “Jose Chung’s From Outer Space,” Mulder decries “the military-industrial-entertainment complex”; a few seasons later, in the Duchovny-written and -directed “Hollywood A.D.,” Mulder and Scully are transformed into Garry Shandling and Téa Leoni, in a big-screen, high-octane mangling of their lives.

Such episodes were, to be sure, exceptions. Most weeks, “The X-Files”unrolled at a deliberate, dreamy pace that was echoed in the measured energy of its leads. Both Duchovny and Anderson had a softness, even a sleepiness, superficially at odds with their roles as FBI agents and action heroes. They were not dry and deadpan, exactly (though they were, through the years, increasingly droll.) Theirs was a kind of restrained sensuality, a narcotic eroticism.

(I mean no disrespect to Robert Patrick or Annabeth Gish, who as agents Doggett and Reyes slid into lead roles in the last couple of seasons — seasons that certainly had some good and even great episodes — but they are somewhat beside the point.)

Scully and Mulder, Mulder and Scully — pivoting on that central “ul,” you can begin with one name and end with the other: Mully. Sculder. They are two sides of the same coin, interlocking yin and yang, one unthinkable without the other. It was therefore the custom of the show to endanger them in turns — to abduct, imprison, experiment upon and/or sicken them, in order to turn up the feeling.

Carter kept them scrupulously out of each other’s arms for most of the show’s run; their commitment was to the Job, and to the out-there Truth. For the first five or six seasons they were less Romeo and Juliet than they were Hansel and Gretel, wandering in the woods (there were a lot of woods in “The X-Files”), flashlights in hand.

For fans who wanted to see them romantically engaged, Carter’s refusal did nothing to dampen that desire, and likely compounded it. Eventually, he did bring them together, or stopped keeping them apart. Even then, though, the relationship was more glimpsed than explored — as if to say, yes, viewer, we will give this to you, and no, it is really none of your business.

When last seen, at the end of the credits to the 2008 “The X-Files: I Want to Believe” — the second film sprung from the series, released six years after the end of its run — they were rowing toward a tropical island (having spent the rest of the movie in the snow.)

For all we know, they are there still.

The episode “Jose Chung’s From Outer Space” will screen as part of the Hero Complex Film Festival on Sunday evening in Hollywood. Look for more coverage from the festival, including from the 20th anniversary tribute to “The X-Files” featuring special guest Chris Carter, in the coming days. And feel free to leave your favorite “X-Files” memory in the comments below.