Ancona liked it. She paused the episode, rewound it and opened Shazam, an app that identifies songs, but it couldn’t find a match. Details about the track weren’t on an IMDb page about the episode either. Perplexed, Ancona searched for the lyrics online and found nothing — except forum posts from other “X-Files” fans asking the same question. Some said they’d been searching since 1998, when the episode first aired.

It was a mystery fit for Mulder and Scully themselves. Who was the songwriter behind the mysterious country tune with no name and no credit? And how had legions of “X-Files” fans failed to identify it in 25 years?

Ancona wanted to crack the case, if only so the uncredited creators of the song could get their due.

“I wanted them to know that they were appreciated,” she told The Washington Post.

Ancona posed the question on X, formerly Twitter. Then she went to bed. She woke up to a viral thread that would eventually draw over 1,000 comments and millions of views. Fans and industry experts chimed in, and in less than 24 hours, a horde of social media sleuths had found the answer and contacted the writers who made the song.

Ancona got her wish — her idle curiosity had led the internet to solve a decades-old mystery and recognize the forgotten work of a pair of veteran composers who were shocked and delighted to see they’d earned viral fame.

“Twenty-five years!” Ancona said. “They had no idea that their tune was this kind of cult thing. It’s amazing.”

The internet had led Ancona to Dan Marfisi and Glenn Jordan, two Los Angeles-based musicians who composed music for TV and movie productions in the ’90s.

“Staring at the Stars” was an original country song that Marfisi and Jordan wrote at the request of “X-Files” producers, Marfisi told The Post. The two musicians — longtime friends and collaborators who met in Los Angeles — were given an unorthodox brief to fit the science-fiction show.

“We got a directive … for a country song that could be about an alien or a human being,” Marfisi said. “And we had to do it really fast.”

The two quickly put together a soothing country track with a soft drumbeat and pedal steel guitar that hid an extraterrestrial theme in the lyrics, sung by Jordan: “In my memory you are moonlight, starlight/With big dark eyes that send me out of sight …”

“What they wanted us to capture was something that just said ‘country bar,’” Jordan said. “Putting the lyrics on about [aliens] was just kind of a little bit of a tongue-in-cheek thing.”

The duo completed the song and sent it off to the producers. Then they moved on. The song was used in “Dreamland II,” the fifth episode of the show’s sixth season. Because it was never released elsewhere — “It was certainly wasn’t the kind of song that the publishers in Nashville … were looking for,” Jordan said — there was little record of its production and the two musicians who’d crafted it.

Marfisi and Jordan had no idea that after more than two decades, their ditty would unite the internet in a frenetic online search.

Ancona, who works in web analytics in Philadelphia, watched with excitement on Tuesday as her post on X gained traction. Ancona had worked previously as a social media manager and knew the thrills — and pitfalls — of achieving viral fame online, she said. But this thread felt different. There were no trolls or naysayers, just a flood of television fans and music professionals invested in the mystery and eager to help.

“It was such a pleasant thing to go viral for,” Ancona laughed.

In the comments below Ancona’s original tweet, clues and breadcrumbs surfaced. Someone contacted the episode’s credited music editor, who couldn’t remember the track. Another user found the episode’s production cue sheet, which listed the durations of the songs played in the episode, but not the titles. Ancona purchased the episode on Amazon and timed the country song with a stopwatch.

Finally, on Tuesday evening, a Los Angeles film and TV music supervisor commented on the thread with a breakthrough, naming Marfisi and Jordan.

Marfisi said a friend called him on Tuesday to tell him that an old song from his catalogue was blowing up online. Marfisi couldn’t believe it.

“The first thing you think of when somebody goes, ‘Hey, we’re viral on Twitter!’ is like … what have I done stupid lately?” he said.

Marfisi called Jordan, who was just as stunned. Marfisi no longer had a copy of “Staring at the Stars,” but Jordan dug through his records and found the song saved on a CD. Finally, Marfisi posted on Ancona’s thread, ending the search with an excited confirmation that the sleuths had found their quarry.

“Oh, I was so stoked,” Ancona said.

Marfisi and Jordan said they were stunned by the passionate reaction to their song, one of hundreds they’d written for productions over the years without expecting a blockbuster response.

“It’s so weird and wonderful,” Marfisi said. “I’m just kind of loving what’s happening. People are talking about Glenn’s and my song? That’s what you want when you’re a musician. You want people to listen and get something from it.”

The two musicians, who haven’t collaborated in recent years because of family commitments, reconnected for the first time in years Wednesday when Marfisi drove to Jordan’s house in Van Nuys to collect the CD. They sat together and listened to their 25-year-old track again, knowing now that it had resonated with fans for decades.

“Dan and I were both walking around with big smiles on our faces,” Jordan said.

Marfisi announced on X that the duo intends to finally release the song soon, ensuring that the catchy song from “The X-Files” will live on — with the names of its creators attached.

“Everybody always wonders if they’re going to be the subject of something viral online,” Marfisi said. “But I’m happy, we’re both very happy that it happened this way.”