After 13 years off the air, they’ve re-opened The X-Files. Here’s what you need to know about the show’s return and the one thing you need to bring to the couch: Patience.

Do you still believe in The X-Files? Is their audience still out there?

FOX certainly hopes so. They’ve promoted the hell out of the upcoming “event series” and are giving it a splashy two-night premiere with a high-profile launch pad: premiering this Sunday, Jan. 24, at 10 p.m. EST, following the NFC Championship Game, (then continuing with its time-period premiere on Monday, Jan. 25 at 8/7c).

The network is on a reboot roll lately, reviving not just The X-Files, but also former hits Prison Break for a sequel and 24: Legacy, a spinoff –– gasp! –– without Jack Bauer.

At least The X-Files has Mulder and Scully. Both David Duchovny and Gillian Anderson return to the roles that made them famous for the next chapter of the alien-hunting conspiracy-theorist saga. Or as series creator/executive producer Chris Carter likes to say, “We’re getting the band back together.”

“As much as I wanted to get away from Mulder at a certain point, I always hoped and knew, if there was a demand, we would be able to come back and visit from time to time,” Duchovny said of suiting back up as Mulder during an interview with Bio and a small group of reporters while promoting the show last week at the TCA Winter Press Tour in Pasadena.

The X-Files Revival Photo

Mitch Pileggi, David Duchovny, Gillian Anderson and William B. Davis. (Photo: Frank Ockenfels/FOX)

For the uninitiated, The X-Files was a basement-run unit of the FBI, headed up by FBI Agents Fox Mulder and Dana Scully, where they investigated, and/or debunked, unexplained cases of the paranormal sort until they were shut down. During its ‘90s heyday, the show was true pop-culture phenomenon that ran for nine mostly successful seasons and spawned two feature films (one a hit, one a flop).

That brings us to the six new episodes created as a limited-run “event series” that plays the nostalgia card in spades. Diehard fans will get the tingles the moment the iconic theme music begins to play. Then a few unfortunate things happen.

Mostly due to the passage of time and the need to catch-up both new and old fans alike, the premiere is filled with clunky exposition that clutters the episode. The opening scene, in fact, serves as a giant recap, and later, Duchovny and guest star Joel McHale rattle off a mountain of dialogue that pretty much explains everything you need to know about The X-Files in one mind-boggling scene. I can’t say that it helps.

Nor does the odd casting of McHale (yes, the sarcastic one from The Soup and Community), who plays a Bill O’Reilly type named Tad O’Malley. He’s the one who ropes the dynamic duo back into the UFO biz when he introduces them to an alleged alien abductee.

That brings us to another problem: the Mulder situation. It seems our dear Fox Mulder has become a doubting Thomas. After being told that everything he’s believed all these years is “nonsense,” we now have a Mulder who no longer believes. Um, WHAT? That’s a wildly out-of-character plot convention. Scully was always the skeptic, Mulder was always the believer. The role reversal sets the next chapter in motion, but don’t worry, it won’t last long.

The X-Files Revival Photo

David Duchovny and Gillian Anderson. (Photo: Frank Ockenfels/FOX)

“Mulder was always like the engine of the show,” Duchovny told us. “He’s the guy putting his foot on the gas.”

But he was a bit rusty getting back behind the wheel as Mulder (and it shows).

“It was more familiar to me once Mulder got re-invested in The X-Files, after the first episode,” Duchovny admitted. His performance noticeably gets better after Mulder gets back to his old self, and as Scully herself says at one point, “Yeah, this is how I like my Mulder.” Me too, Scully, me too.

We’ve seen three of the six new episodes, and here’s what we can tell you: many things are amiss in the first hour; the second episode gets better; and by the third, things are really back in gear. If you’re patient and stick with it, the payoff comes in that hour.

That third installment, penned by X-Files veteran Darin Morgan, is an irony-filled comedic outing called “Mulder & Scully Meet the Were-Monster,” and it’s a classic X-Files episode that’s very entertaining. (Just watch Mulder chasing a monster around with his camera phone trying to get a photo…because now they have smartphones! And Internet!...a conspiracy-theorist haven!)

Fun, but also a challenge for the actors.

The X-Files Reboot Joel McHale Photo

David Duchovny, Gillian Anderson and guest star Joel McHale. (Photo: Ed Araquel/FOX)

“It’s very tricky as an actor to find the right tone all the time on this particular show," said Duchovny. "[It’s] a thriller, a horror, a mystery, a quest, a comedy…"

He added: “It can be a little scary too. When we were in the middle of [shooting] the Darin [Morgan] episode, we were like, 'Holy sh*t, what are we doing? Is this really working?' We don’t know. It’s a little trippy.”

And that’s just how we like our X-Files: a little trippy.

Here are 5 More Things to Know about The X-Files reboot:

1. Mulder and Scully aren’t together any more.

As the show opens, it’s revealed that Mulder and Scully have been living separate lives. Scully is back to being a doctor, while a scruffy Mulder has been off by himself living as something of a recluse. But they clearly still have a soft spot for each other and their complicated relationship history is at the core of the story. Look for Episode 2 to touch upon William, the baby Mulder and Scully had together and gave up for adoption.

2. But the chemistry is still there.

“Having known each other and worked together so much for the last over 20 years, we’ve gone beyond chemistry into history… so we don’t have to play it,” Duchovny told reporters of the pair’s relationship during a TCA press conference last week. “Now we have chemistry and history…we’re going to try and get biology, too,” he joked.

3. Who’s back?

Mulder and Scully, of course. Their boss, FBI Asst. Director Walter Skinner (Mitch Pileggi), is back, too. Annabeth Gish returns as FBI Agent Monica Reyes. And despite apparently dying in the series finale, William B. Davis reprises his role as the all-knowing and ever-mysterious “Cigarette Smoking Man.” The Lone Gunman, who also perished in the original series, pop-up at some point as well, in a fantasy sequence, according to Chris Carter.

In addition to the previously mentioned Joel McHale, the six new episodes will also feature guest-star appearances by Robbie Amell (The Flash), Lauren Ambrose (Six Feet Under), Annet Mahendru (The Americans), Rhys Darby (Flight of the Conchords) and Kumail Nanjiani (Silicon Valley).

4. What to expect in those six new episodes?

The “event series” contains four stand-alone “monster-of-the-week” episodes, bookended by two mythology episodes that further the show’s original overall arc.

Series creator/executive producer Chris Carter wrote three of the new episodes, while the other three installments come from series veterans Glen Morgan, Darin Morgan and James Wong. Filming returned to the original set location of Vancouver so the look and feel are consistent with the original, too.

5. Will there be more?

“It depends on how it does, but I bet we would come back for another iteration,” Duchovny said, telling us he’d be up for another six- or eight-episode run. “But not for 22 or 24 episodes,” he explained. “We’re just too old…Can’t work that hard.”

The X-Files premieres Sunday, Jan. 24, at 10 p.m. EST, on FOX, following the NFC Championship Game, and continues in its time-period premiere on Monday, Jan. 25 at 8 p.m. EST.