– There may be millions of believers eager for the reopening of “The X-Files,” but you wouldn’t necessarily expect Gillian Anderson and David Duchovny to be among them.

In the 13 years since the show went off the air, the actors have done their best to distance themselves from the iconic roles of Dana Scully and Fox Mulder. Anderson is in such demand for European-set period dramas that she had the luxury of turning down the role of the countess of Grantham in “Downton Abbey.” Duchovny committed to Showtime’s “Californication,” playing the hedonistic Hank Moody, who would be interested only in aliens hailing from the Planet of Loose Women.

Yes, there was the 2008 “X-Files” feature film “I Want to Believe,” but the plot, as I best recall, consisted of little more than the special agents impatiently waiting for a spaceship to drop off their paychecks.

But the actors seemed downright giddy to be slipping into their old skins during a promotional tour for a new six-episode revival, which starts Sunday, flirting with each other like kids on a prom date.

Either the pair are truly grateful to take a trip down memory lane, or they’re the greatest actors of their generation.

The upbeat mood is especially surprising from Anderson, who early in her career thought she’d be doing work more akin to “Prime Suspect” than Comic-Con catnip.

“When I was cast in ‘The X-Files,’ it was just a little off to the left of where I had seen my career choices to be, and I got swept up into that,” said Anderson, who was practically unknown when the Fox series made its 1993 debut. “It took a good decade for me to properly appreciate the opportunity that I had, and also how fortunate I was to play such a great iconic character in a show that was iconic in and of itself. I think it suddenly hit me some time later.”

Duchovny also seems to have come to terms with the fact that, unless he’s cast as the next James Bond, he’ll always be best known as Foxy Fox.

“It took awhile to recognize it as the gift that it is, and that’s why we’re able to come back now,” he said. “And I think also maybe it served as a spur to me to go out and actually do more work, to keep expanding myself as an artist.”

‘Not a victory lap’

One person who never stopped believing was creator Chris Carter. Skeptics might theorize that that’s because nothing else has really worked for him. He hasn’t produced or written any successful material unassociated with “The X-Files” in his nearly 30-year career. Keep in mind, however, that the “Files” world, which could morph from week to week, always allowed him to show off his storytelling skills in various genres, much in the same way Rod Serling used “The Twilight Zone.”

This truncated season follows the same anything-goes approach, with episodes ranging from horror — mutant kids terrorize their keepers — to broad comedy, particularly in the third installment, where a were-lizard reluctantly takes on a human facade and has to work in a cellphone store.

“We are coming back to do really fresh, original material, not a victory lap,” said Carter, who had planned to revive “X-Files” on the big screen until his wife persuaded him to return to TV. “This is an opportunity to show people that the show has more life to it.”

If the first incarnation of the series reflected Carter’s upbringing during the age of Watergate, the reboot fits snugly into an era where some people are convinced 9/11 was a government conspiracy and President Obama is covering up his true birthplace.

“We’re living in a time now when there’s a tremendous amount of distrust of authority, government, even the media, so this is a really interesting time to be telling ‘X-Files’ stories,” Carter said.

Satisfying the superfans

Carter’s still healthy — or unhealthy — state of paranoia is welcome news to superfans, a group that includes actor Joel McHale, who appears as a possible ally to the agents in the first and sixth episodes.

“This is like winning an auction item,” he said. “My wife and I went to the premiere two nights ago, and every time I walked into a scene she burst out laughing because of my acting and because it was the show that, before we were married, we would sit on a couch and watch because everything came together for both of us in it.”

For McHale, it was the science fiction. For her, it was the relationship between Mulder and Scully. Both should be satisfied with the new episodes. Especially her.

Carter said the chemistry was there the moment Anderson and Duchovny shot the very first scene together back in 1993.

“It wasn’t until the day they both appeared in Mulder’s office that I saw that they just both lit up, and it’s been the same ever since,” he said. “It’s one of those things that you can’t manufacture. It just happens, and we got very, very lucky.”