Several writers behind Alias reunited Saturday at the ATX Television Festival in Austin, Texas, to reveal secrets and behind-the-scenes stories from the beloved former ABC spy drama.

Premiering in 2001, Alias centered on Sydney Bristow (Jennifer Garner), a double-agent for the CIA posing as an agent for the criminal organization SD-6. Created by J.J. Abrams, the series spanned five seasons and 105 episodes. Although it's been more than a decade since the show ended, it continues to resonate with its die-hard fans

"One of things that made this show really special was this girl is really badass," writer-producer-director Ken Olin said of the "empowering" action-heavy series.

Olin, along with writers Sarah Caplan, Andre Nemec, Josh Appelbaum and Monica Owusu-Breen, spilled lots more stories about celebrity guest stars, the truth about Alias' complicated Rambaldi mythology and a potential revival. Read on for highlights.

Premiering After 9/11

Alias debuted just weeks after the devastating terror attacks in New York City, which left many on the series and at the network wondering, "Is this show even appropriate now?" said Olin, who recalled filming on the day of the attacks. "I was shooting an episode that ended with Sydney wearing a hood and holding a bomb in her hand. The show was done, always, with a sense of humor. If we lost that sense of humor, we were losing the fundamental tone of the show," he recalled. "We got through a lot, but it was strange then. Everything was strange then."

The Truth About the Red Hair

In the first episode, Sydney famously donned a red wig, which proved more difficult to figure out than it sounds. "We had three red hair wigs and none of them were good enough," Caplan recalled. "[Abrams] was like, 'It's not the right red, it's not the right red."

When scouting locations at UCLA, Caplan and Abrams found a math student who had the exact right shade of red. "I went up to the girl, I said, 'Do you mind if I take a little snippet of your hair?'" Caplan said. "She looks at me and she says no." Eventually, Caplan and Abrams were able to change her mind with $39 dollars from various members of the crew.

Casting Jennifer Garner

When it came to the stunts, "for the first two years, [Garner] did almost everything," Olin said. "She loved doing the stunts, she loved the languages, everything you could throw at her." The only time the actress couldn't do her own fight scenes was when she was pregnant in real life at the end of the fourth season. However, Caplan was the only one who knew. "The director kept saying, 'I need Jennifer up here, she needs to do this fight,' recalled Caplan. "I said, 'She's not coming,' He could not get his head around it for the longest time."

In addition to her intense action sequences, Garner also had heavy emotional scenes, Olin pointed out, as she was learning Mandarin Chinese for the role and also juggling publicity duties on the weekend. "We broke her, eventually," Olin said with a laugh. "We were all like, 'How are we going to break her?' But it was extraordinary, her stamina — it was phenomenal."

The Secrets Behind "Phase One" Reset

Alias earned the coveted post-Super Bowl spot in season two. The famous episode titled "Phase One" reset the entire show when Sydney and the CIA finally invaded SD-6. However, the original episode was supposed to be the hour that featured Ethan Hawke. "We shot another show that was going to be [post-Super Bowl]," said Caplan. "And when we were making it, I go, 'J.J., this is a really dark show.'"

That meant a quick turnaround for the new episode, which was a pivotal one. "Suddenly, we're racing to do this show. I think that the postproduction lady, somehow she made it, she took about four days to turn the visual effects around on that," Caplan said. "It was unbelievably stressful to get that episode out in time."

The huge reset creatively served as inspiration for the rest of the writing team for the remainder of the series. "It inspired the writers room because then we knew at any moment, we could turn the show on its head," Appelbaum said.

"The willingness to not throw it away but start over, to radically shift the show," Owusu-Breen added. "J.J. was fearless this way and as a writer, it keeps you on your toes: How do you make this show with an entirely different world?"

However, the writers admitted not always telling the actors about what similar twists were in the works, such as when it was revealed Vaughn (Michael Vartan) was not actually Vaughn. Appelbaum recalled "the door to the writers room bursting open and Jen's there and she's like, 'Are you guys kidding me?!' Half the fun was not telling them."

Celebrity Guest Stars

The show had a very eclectic list of guest stars over the years, ranging from Quentin Tarantino to Ricky Gervais. So how did Abrams decide who to cast? "I think it was who J.J. wanted to meet," Caplan joked. About Gervais, Appelbaum recalled the mission to get the comic actor: "[Abrams] got obsessed with the British Office — 'I think if we write something really cool, we can get this guy to fly in.'"

There was one slight problem with Tarantino, however. "Sometimes he'd hit Jennifer by mistake," Caplan revealed. "He's not a great stunt guy," Olin joked, adding more seriously, "He was great, he was just really really into it."

One of the most difficult guest stars was Lena Olin, who played Sydney's absentee mother, who was introduced in season two. "She was very difficult to get her to be on the show, but once she was there she was happy as a clam," Caplan said. "It was weird that it was so hard to get her each time to come and do it."

The Mystery of Rambaldi Explained (Kind of)

Caplan got huge laughs from the room when she admitted she didn't exactly understand the show's complex mythology. "I didn't realize that it was going to be the thing that followed me for several years," she said. "But it did. I cannot explain it to you in this life."

Olin said that was one part of the complicated first-season production. "We just really were trying to get through it," he said. "It was so complicated." Other writers who came on the show later "had a very basic sense of it," said Owusu-Breen. "But Rambaldi was this onion to be unpeeled, so there was a lot of discovering of new Rambaldi stuff along the way."

The Final Season

"We came into season five knowing that that was going to be the last year because again we knew about the pregnancy," Nemec said about Garner's real-life motherhood-to-be. Her blossoming career was also a factor. "Jennifer was a huge star, and Jennifer was now in her thirties and she really wanted a family, so I think there were practical considerations going on as well," Olin said. "Her contract was up and it was clear she needed this time to have her children. And it seemed right." He added with a laugh: "We had burned through so much story!"

Because of Garner's pregnancy and her limited stunts, several new agents were introduced. "It did take on a different dynamic," said Nemec, who added there was never talk about a potential spinoff with the new agents. "I think at the time it felt like if it wasn’t Jen, it wasn't Alias."

A Potential Revival?

The original series left an open thread about Sydney's daughter that could be revisited in a reboot. "It would be amazing to do it," Appelbaum said. "But the right idea would have to come. We wouldn’t want to do it unless it was absolutely perfect."