Stars David Duchovny and Gillian Anderson visited memory lane at Comic-Con panel.

SAN DIEGO -- It's been 20 years since Fox's The X-Files opened the door to a new era of TV science fiction, merging scary monster investigations with a deep, ongoing mythology rooted in conspiracy theory.

Fans at Comic-Con celebrated the series today with a 20th anniversary panel featuring David Duchovny and Gillian Anderson, who played FBI agents Fox Mulder and Dana Scully. The former was a believer in the paranormal, the latter a skeptic, and together they made up a law-enforcement odd couple that mesmerized the popular culture.

The hit series also was one of the shows that helped put a then-young Fox on the network map.

X-Files creator Chris Carter also attended, as did writer-producers of the show who went on to their own big projects, including Howard Gordon (Homeland) and Vince Gilligan (Breaking Bad). Their shows received Emmy nominations earlier in the day.

Both Duchovny and Anderson said they were open to a third X-Files movie, but Carter was non-committal.

As the panel opened, Duchovny and Anderson entered the darkened stage, shining flashlights at the audience, which responded with a standing ovation.

Asked about Mulder and Scully getting together romantically, Duchovny joked, "I'm not sure if we ever did, did we?"

"Something happened," Anderson said, "because we have a child."

The playfulness continued during fan questioning.

Asked what Scully and Mulder might do on a date, Anderson said, "Have sex."

"Then, maybe dinner?" Duchovny responded.

Anderson acknowledged Scully's influence as a strong female character."Scully had quite a huge impact on people, aspects of her personality and her personal strength, things she stood up for. She also was a decent human being."

Carter called her his fantasy woman. "She was strong and smart, opinionated, resourceful, tough," he said.

Duchovny said it would be difficult to act with Anderson again in other roles.

"I've always felt like there was something so special about Mulder and Scully," he said. "I love Gillian (but) It would have to be something I can't think of to cross that line."